diff --git a/src/classes/action/__init__.py b/src/classes/action/__init__.py
index 960cf11..6dfa348 100644
--- a/src/classes/action/__init__.py
+++ b/src/classes/action/__init__.py
@@ -25,7 +25,7 @@ from .breakthrough import Breakthrough
 from .play import Play
 from .hunt import Hunt
 from .harvest import Harvest
-from .sold import SellItems
+from .sell import SellItems
 from .attack import Attack
 from .plunder_mortals import PlunderMortals
 from .help_mortals import HelpMortals
diff --git a/src/classes/action/sold.py b/src/classes/action/sell.py
similarity index 76%
rename from src/classes/action/sold.py
rename to src/classes/action/sell.py
index ec54f32..fbca4d7 100644
--- a/src/classes/action/sold.py
+++ b/src/classes/action/sell.py
@@ -4,14 +4,13 @@ from src.classes.action import InstantAction
 from src.classes.event import Event
 from src.classes.region import CityRegion
 from src.classes.item import items_by_name
-from src.classes.prices import prices
 from src.classes.normalize import normalize_item_name
 
 
 class SellItems(InstantAction):
     """
     在城镇出售指定名称的物品，一次性卖出持有的全部数量。
-    收益为 item_price * item_num，动作耗时1个月。
+    收益通过 avatar.sell_item() 结算。
     """
 
     ACTION_NAME = "出售物品"
@@ -37,21 +36,8 @@ class SellItems(InstantAction):
         if quantity <= 0:
             return
 
-        # 计算价格并结算
-        price_per = prices.get_price(item)
-        base_total_gain = price_per * quantity
-        
-        # 应用出售价格倍率加成
-        price_multiplier_raw = self.avatar.effects.get("extra_item_sell_price_multiplier", 0.0)
-        price_multiplier = 1.0 + float(price_multiplier_raw or 0.0)
-        total_gain = int(base_total_gain * price_multiplier)
-
-        # 扣除物品并增加灵石
-        removed = self.avatar.remove_item(item, quantity)
-        if not removed:
-            return
-
-        self.avatar.magic_stone = self.avatar.magic_stone + total_gain
+        # 通过统一接口出售
+        self.avatar.sell_item(item, quantity)
 
     def can_start(self, item_name: str | None = None) -> tuple[bool, str]:
         region = self.avatar.tile.region
@@ -78,9 +64,6 @@ class SellItems(InstantAction):
         display_name = item.name if item is not None else normalized_name
         return Event(self.world.month_stamp, f"{self.avatar.name} 在城镇出售 {display_name}", related_avatars=[self.avatar.id])
 
-    # InstantAction 已实现 step 完成
-
     async def finish(self, item_name: str) -> list[Event]:
         return []
 
-
diff --git a/src/classes/avatar/info_presenter.py b/src/classes/avatar/info_presenter.py
index aae12cc..4500335 100644
--- a/src/classes/avatar/info_presenter.py
+++ b/src/classes/avatar/info_presenter.py
@@ -28,8 +28,8 @@ def get_avatar_info(avatar: "Avatar", detailed: bool = False) -> dict:
     from src.classes.sect import get_sect_info_with_rank
     
     if detailed:
-        weapon_info = f"{avatar.weapon.get_detailed_info()}，熟练度：{avatar.weapon_proficiency:.1f}%"
-        auxiliary_info = avatar.auxiliary.get_detailed_info() if avatar.auxiliary is not None else "无"
+        weapon_info = f"{avatar.weapon.get_detailed_info()}，熟练度：{avatar.weapon_proficiency:.1f}%" if avatar.weapon else "无"
+        auxiliary_info = avatar.auxiliary.get_detailed_info() if avatar.auxiliary else "无"
         sect_info = get_sect_info_with_rank(avatar, detailed=True)
         alignment_info = avatar.alignment.get_detailed_info() if avatar.alignment is not None else "未知"
         region_info = region.get_detailed_info() if region is not None else "无"
diff --git a/src/classes/avatar/inventory_mixin.py b/src/classes/avatar/inventory_mixin.py
index 03a79dc..aad373a 100644
--- a/src/classes/avatar/inventory_mixin.py
+++ b/src/classes/avatar/inventory_mixin.py
@@ -104,3 +104,50 @@ class InventoryMixin:
         actual_amount = amount * gain_multiplier
         self.weapon_proficiency = min(100.0, self.weapon_proficiency + actual_amount)
 
+    # ==================== 出售接口 ====================
+    
+    def _get_sell_multiplier(self: "Avatar") -> float:
+        """获取出售价格倍率（包含效果加成）"""
+        raw = self.effects.get("extra_item_sell_price_multiplier", 0.0)
+        return 1.0 + float(raw or 0.0)
+
+    def sell_item(self: "Avatar", item: "Item", quantity: int = 1) -> int:
+        """
+        出售材料物品，返回获得的灵石数量。
+        应用 extra_item_sell_price_multiplier 效果。
+        """
+        from src.classes.prices import prices
+        
+        if quantity <= 0 or self.get_item_quantity(item) < quantity:
+            return 0
+        
+        self.remove_item(item, quantity)
+        
+        base_price = prices.get_item_price(item) * quantity
+        total = int(base_price * self._get_sell_multiplier())
+        
+        self.magic_stone = self.magic_stone + total
+        return total
+
+    def sell_weapon(self: "Avatar", weapon: "Weapon") -> int:
+        """
+        出售兵器，返回获得的灵石数量。
+        注意：这是辅助方法，不会自动卸下当前装备。
+        """
+        from src.classes.prices import prices
+        
+        total = int(prices.get_weapon_price(weapon) * self._get_sell_multiplier())
+        self.magic_stone = self.magic_stone + total
+        return total
+
+    def sell_auxiliary(self: "Avatar", auxiliary: "Auxiliary") -> int:
+        """
+        出售辅助装备，返回获得的灵石数量。
+        注意：这是辅助方法，不会自动卸下当前装备。
+        """
+        from src.classes.prices import prices
+        
+        total = int(prices.get_auxiliary_price(auxiliary) * self._get_sell_multiplier())
+        self.magic_stone = self.magic_stone + total
+        return total
+
diff --git a/src/classes/fortune.py b/src/classes/fortune.py
index c6aa261..018c906 100644
--- a/src/classes/fortune.py
+++ b/src/classes/fortune.py
@@ -423,7 +423,7 @@ async def try_trigger_fortune(avatar: Avatar) -> list[Event]:
             },
             {
                 "key": "B", 
-                "desc": f"放弃原{type_label}，接受新{type_label}『{new_name}』({new_grade_val})。"
+                "desc": f"卖掉原{type_label}『{old_name}』换取灵石，接受新{type_label}『{new_name}』({new_grade_val})。"
             }
         ]
         
@@ -435,7 +435,7 @@ async def try_trigger_fortune(avatar: Avatar) -> list[Event]:
         if choice == "A":
             return False, f"{avatar.name} 放弃了{new_grade_val}{type_label}『{new_name}』，保留了『{old_name}』"
         else:
-            return True, f"{avatar.name} 获得了{new_grade_val}{type_label}『{new_name}』，替换了『{old_name}』"
+            return True, f"{avatar.name} 获得了{new_grade_val}{type_label}『{new_name}』，卖掉了『{old_name}』"
 
     if kind == FortuneKind.WEAPON:
         weapon = _get_weapon_for_avatar(avatar)
@@ -448,6 +448,9 @@ async def try_trigger_fortune(avatar: Avatar) -> list[Event]:
                 weapon, avatar.weapon, "兵器"
             )
             if should_equip:
+                # 自动卖掉旧武器
+                if avatar.weapon is not None:
+                    avatar.sell_weapon(avatar.weapon)
                 avatar.change_weapon(weapon)
 
     if kind == FortuneKind.AUXILIARY:
@@ -461,6 +464,9 @@ async def try_trigger_fortune(avatar: Avatar) -> list[Event]:
                 auxiliary, avatar.auxiliary, "辅助装备"
             )
             if should_equip:
+                # 自动卖掉旧辅助装备
+                if avatar.auxiliary is not None:
+                    avatar.sell_auxiliary(avatar.auxiliary)
                 avatar.change_auxiliary(auxiliary)
 
     if kind == FortuneKind.TECHNIQUE:
diff --git a/src/classes/kill_and_grab.py b/src/classes/kill_and_grab.py
index bf4a952..7b762cd 100644
--- a/src/classes/kill_and_grab.py
+++ b/src/classes/kill_and_grab.py
@@ -56,7 +56,7 @@ async def kill_and_grab(winner: Avatar, loser: Avatar) -> str:
         options = [
             {
                 "key": "A",
-                "desc": f"夺取『{loot_item.name}』，替换掉身上的『{winner_current.name}』。\n  - 新装备：{item_desc}\n  - 原装备：{current_desc}"
+                "desc": f"夺取『{loot_item.name}』，卖掉身上的『{winner_current.name}』换取灵石。\n  - 新装备：{item_desc}\n  - 原装备：{current_desc}"
             },
             {
                 "key": "B",
@@ -69,9 +69,15 @@ async def kill_and_grab(winner: Avatar, loser: Avatar) -> str:
     
     if should_loot:
         if loot_type == "weapon":
+            # 自动卖掉旧武器
+            if winner.weapon is not None:
+                winner.sell_weapon(winner.weapon)
             winner.change_weapon(loot_item)
             loser.change_weapon(None)
         else:
+            # 自动卖掉旧辅助装备
+            if winner.auxiliary is not None:
+                winner.sell_auxiliary(winner.auxiliary)
             winner.change_auxiliary(loot_item)
             loser.change_auxiliary(None)
         
diff --git a/src/classes/prices.py b/src/classes/prices.py
index 0e0e0ac..53abf2f 100644
--- a/src/classes/prices.py
+++ b/src/classes/prices.py
@@ -1,23 +1,89 @@
+"""
+统一价格系统
+============
+
+所有物品/装备的价格通过这个模块获取。
+价格只和对应的 realm 绑定，全局统一。
+
+价格设计参考（以练气期年收入约 20-30 灵石为基准）：
+- 材料(Item): 采集物等消耗品
+- 兵器(Weapon): 稀有装备，价值较高
+- 辅助装备(Auxiliary): 法宝等，价值次于兵器
+"""
+from __future__ import annotations
+
+from typing import Union, TYPE_CHECKING
+
 from src.classes.cultivation import Realm
-from src.classes.item import Item
+
+if TYPE_CHECKING:
+    from src.classes.item import Item
+    from src.classes.weapon import Weapon
+    from src.classes.auxiliary import Auxiliary
+
+# 类型别名
+Sellable = Union["Item", "Weapon", "Auxiliary"]
+
 
 class Prices:
     """
     价格体系。
-    刚开始我只准备做一个比较简单的价格体系，之后可能复杂化。
-    目前是所有的城镇都可以出售材料，同时这些材料的价格是固定的，并且全局公开。
-    价格只和对应的realm绑定。
+    所有城镇可交易物品/装备的价格在此统一管理。
     """
-    def __init__(self):
-        self.realm_to_prices = {
-            Realm.Qi_Refinement: 10,
-            Realm.Foundation_Establishment: 50,
-            Realm.Core_Formation: 100,
-            Realm.Nascent_Soul: 200,
-        }
+    
+    # 材料价格表（采集物等）
+    ITEM_PRICES = {
+        Realm.Qi_Refinement: 10,
+        Realm.Foundation_Establishment: 30,
+        Realm.Core_Formation: 60,
+        Realm.Nascent_Soul: 100,
+    }
+    
+    # 兵器价格表（稀有，价值高）
+    WEAPON_PRICES = {
+        Realm.Qi_Refinement: 10,
+        Realm.Foundation_Establishment: 300,
+        Realm.Core_Formation: 1000,
+        Realm.Nascent_Soul: 2000,
+    }
+    
+    # 辅助装备价格表
+    AUXILIARY_PRICES = {
+        Realm.Qi_Refinement: 10,
+        Realm.Foundation_Establishment: 250,
+        Realm.Core_Formation: 800,
+        Realm.Nascent_Soul: 1600,
+    }
+    
+    def get_item_price(self, item: "Item") -> int:
+        """获取材料价格"""
+        return self.ITEM_PRICES.get(item.realm, 10)
+    
+    def get_weapon_price(self, weapon: "Weapon") -> int:
+        """获取兵器价格"""
+        return self.WEAPON_PRICES.get(weapon.realm, 100)
+    
+    def get_auxiliary_price(self, auxiliary: "Auxiliary") -> int:
+        """获取辅助装备价格"""
+        return self.AUXILIARY_PRICES.get(auxiliary.realm, 80)
+    
+    def get_price(self, obj: Sellable) -> int:
+        """
+        统一价格查询接口。
+        根据对象类型自动分发到对应的价格查询方法。
+        """
+        from src.classes.item import Item
+        from src.classes.weapon import Weapon
+        from src.classes.auxiliary import Auxiliary
+        
+        if isinstance(obj, Item):
+            return self.get_item_price(obj)
+        elif isinstance(obj, Weapon):
+            return self.get_weapon_price(obj)
+        elif isinstance(obj, Auxiliary):
+            return self.get_auxiliary_price(obj)
+        return 0
 
-    def get_price(self, item: Item) -> int:
-        return self.realm_to_prices[item.realm]
 
-# 预先创建全局价格实例，供全局使用
-prices = Prices()
\ No newline at end of file
+# 全局单例
+prices = Prices()
diff --git a/tests/test_prices.py b/tests/test_prices.py
new file mode 100644
index 0000000..d28d888
--- /dev/null
+++ b/tests/test_prices.py
@@ -0,0 +1,178 @@
+import pytest
+import copy
+from unittest.mock import MagicMock, patch
+
+from src.classes.prices import prices, Prices
+from src.classes.cultivation import Realm
+from src.classes.item import items_by_id
+from src.classes.weapon import weapons_by_id, Weapon, get_random_weapon_by_realm
+from src.classes.auxiliary import auxiliaries_by_id, Auxiliary, get_random_auxiliary_by_realm
+
+
+class TestPrices:
+    """价格系统测试"""
+    
+    def test_item_prices_by_realm(self):
+        """测试材料价格按境界递增"""
+        assert prices.ITEM_PRICES[Realm.Qi_Refinement] < prices.ITEM_PRICES[Realm.Foundation_Establishment]
+        assert prices.ITEM_PRICES[Realm.Foundation_Establishment] < prices.ITEM_PRICES[Realm.Core_Formation]
+        assert prices.ITEM_PRICES[Realm.Core_Formation] < prices.ITEM_PRICES[Realm.Nascent_Soul]
+
+    def test_weapon_prices_by_realm(self):
+        """测试兵器价格按境界递增"""
+        assert prices.WEAPON_PRICES[Realm.Qi_Refinement] < prices.WEAPON_PRICES[Realm.Foundation_Establishment]
+        assert prices.WEAPON_PRICES[Realm.Foundation_Establishment] < prices.WEAPON_PRICES[Realm.Core_Formation]
+        assert prices.WEAPON_PRICES[Realm.Core_Formation] < prices.WEAPON_PRICES[Realm.Nascent_Soul]
+
+    def test_auxiliary_prices_by_realm(self):
+        """测试辅助装备价格按境界递增"""
+        assert prices.AUXILIARY_PRICES[Realm.Qi_Refinement] < prices.AUXILIARY_PRICES[Realm.Foundation_Establishment]
+        assert prices.AUXILIARY_PRICES[Realm.Foundation_Establishment] < prices.AUXILIARY_PRICES[Realm.Core_Formation]
+        assert prices.AUXILIARY_PRICES[Realm.Core_Formation] < prices.AUXILIARY_PRICES[Realm.Nascent_Soul]
+
+    def test_get_price_for_item(self):
+        """测试 get_price 对 Item 类型的分发"""
+        if not items_by_id:
+            pytest.skip("No items available in config")
+        
+        item = next(iter(items_by_id.values()))
+        price = prices.get_price(item)
+        expected = prices.get_item_price(item)
+        assert price == expected
+        assert price == prices.ITEM_PRICES[item.realm]
+
+    def test_get_price_for_weapon(self):
+        """测试 get_price 对 Weapon 类型的分发"""
+        if not weapons_by_id:
+            pytest.skip("No weapons available in config")
+        
+        weapon = next(iter(weapons_by_id.values()))
+        price = prices.get_price(weapon)
+        expected = prices.get_weapon_price(weapon)
+        assert price == expected
+        assert price == prices.WEAPON_PRICES[weapon.realm]
+
+    def test_get_price_for_auxiliary(self):
+        """测试 get_price 对 Auxiliary 类型的分发"""
+        if not auxiliaries_by_id:
+            pytest.skip("No auxiliaries available in config")
+        
+        aux = next(iter(auxiliaries_by_id.values()))
+        price = prices.get_price(aux)
+        expected = prices.get_auxiliary_price(aux)
+        assert price == expected
+        assert price == prices.AUXILIARY_PRICES[aux.realm]
+
+    def test_weapon_more_expensive_than_item(self):
+        """测试同境界下兵器比材料贵"""
+        for realm in Realm:
+            if realm in prices.ITEM_PRICES and realm in prices.WEAPON_PRICES:
+                assert prices.WEAPON_PRICES[realm] >= prices.ITEM_PRICES[realm]
+
+
+class TestAvatarSell:
+    """Avatar 出售接口测试"""
+
+    def test_sell_item_basic(self, dummy_avatar):
+        """测试基础材料出售"""
+        if not items_by_id:
+            pytest.skip("No items available in config")
+        
+        item = next(iter(items_by_id.values()))
+        dummy_avatar.items = {}  # 清空背包
+        dummy_avatar.magic_stone.value = 0
+        
+        # 添加物品
+        dummy_avatar.add_item(item, 5)
+        assert dummy_avatar.get_item_quantity(item) == 5
+        
+        # 出售3个
+        gained = dummy_avatar.sell_item(item, 3)
+        
+        expected_price = prices.get_item_price(item) * 3
+        assert gained == expected_price
+        assert dummy_avatar.magic_stone.value == expected_price
+        assert dummy_avatar.get_item_quantity(item) == 2
+
+    def test_sell_item_insufficient(self, dummy_avatar):
+        """测试出售物品数量不足"""
+        if not items_by_id:
+            pytest.skip("No items available in config")
+        
+        item = next(iter(items_by_id.values()))
+        dummy_avatar.items = {}
+        dummy_avatar.magic_stone.value = 100
+        
+        dummy_avatar.add_item(item, 2)
+        
+        # 尝试出售5个（只有2个）
+        gained = dummy_avatar.sell_item(item, 5)
+        
+        assert gained == 0
+        assert dummy_avatar.magic_stone.value == 100  # 没有变化
+        assert dummy_avatar.get_item_quantity(item) == 2  # 物品未减少
+
+    def test_sell_weapon(self, dummy_avatar):
+        """测试出售兵器"""
+        weapon = get_random_weapon_by_realm(Realm.Foundation_Establishment)
+        if not weapon:
+            pytest.skip("No Foundation Establishment weapons available")
+        
+        dummy_avatar.magic_stone.value = 0
+        
+        gained = dummy_avatar.sell_weapon(weapon)
+        
+        expected = prices.get_weapon_price(weapon)
+        assert gained == expected
+        assert dummy_avatar.magic_stone.value == expected
+
+    def test_sell_auxiliary(self, dummy_avatar):
+        """测试出售辅助装备"""
+        aux = get_random_auxiliary_by_realm(Realm.Core_Formation)
+        if not aux:
+            pytest.skip("No Core Formation auxiliaries available")
+        
+        dummy_avatar.magic_stone.value = 0
+        
+        gained = dummy_avatar.sell_auxiliary(aux)
+        
+        expected = prices.get_auxiliary_price(aux)
+        assert gained == expected
+        assert dummy_avatar.magic_stone.value == expected
+
+    def test_sell_with_price_multiplier(self, dummy_avatar):
+        """测试出售价格倍率效果"""
+        if not items_by_id:
+            pytest.skip("No items available in config")
+        
+        item = next(iter(items_by_id.values()))
+        dummy_avatar.items = {}
+        dummy_avatar.magic_stone.value = 0
+        dummy_avatar.add_item(item, 1)
+        
+        base_price = prices.get_item_price(item)
+        
+        # 设置 20% 加成 - patch 内部方法
+        with patch.object(dummy_avatar, '_get_sell_multiplier', return_value=1.2):
+            gained = dummy_avatar.sell_item(item, 1)
+        
+        expected = int(base_price * 1.2)
+        assert gained == expected
+        assert dummy_avatar.magic_stone.value == expected
+
+    def test_sell_weapon_with_multiplier(self, dummy_avatar):
+        """测试出售兵器时价格倍率生效"""
+        weapon = get_random_weapon_by_realm(Realm.Qi_Refinement)
+        if not weapon:
+            pytest.skip("No Qi Refinement weapons available")
+        
+        dummy_avatar.magic_stone.value = 0
+        base_price = prices.get_weapon_price(weapon)
+        
+        # 设置 50% 加成 - patch 内部方法
+        with patch.object(dummy_avatar, '_get_sell_multiplier', return_value=1.5):
+            gained = dummy_avatar.sell_weapon(weapon)
+        
+        expected = int(base_price * 1.5)
+        assert gained == expected
+