diff --git a/src/adv/Adv.lua b/src/adv/Adv.lua
index 7abca0a..4c2278c 100644
--- a/src/adv/Adv.lua
+++ b/src/adv/Adv.lua
@@ -1712,7 +1712,7 @@ local function clickTrader(self, room, block, params)
 	local goodsData = csvdb["event_trader_goodsCsv"][block.event.shop[buyId][1]]
 	if not goodsData then return false, 5 end
 
-	local costCount = math.ceil(goodsData.price * (block.event.shop[buyId][2] or 100) / 100)
+	local costCount = math.ceil(goodsData.price * (1 - (block.event.shop[buyId][2] or 100) / 100))
 	if not self:cost({[goodsData.currency] = costCount}, {log = {desc = "clickTrader", int1 = block.event.id}}) then return false, 6 end --不够
 	self:backCost({[goodsData.currency] = costCount})
 	self:award({[goodsData.item] = goodsData.num}, {log = {desc = "clickTrader", int1 = block.event.id}}, {})
--
libgit2 0.21.2