message: Fix incorrectly set item cost
diff: @@ -193,7 +193,7 @@ void NPCManager::npcVendorBuy(CNSocket* sock, CNPacketData* data) {
  return;
  }
  - int itemCost = item->sellPrice * (item->stackSize > 1 ? req->Item.iOpt : 1);
  + int itemCost = item->buyPrice * (item->stackSize > 1 ? req->Item.iOpt : 1);
  int slot = ItemManager::findFreeSlot(plr);
  if (itemCost > plr->money || slot == -1) {
  // NOTE: VENDOR_ITEM_BUY_FAIL is not actually handled client-side.
  