全服限量抢购：库存售罄即停的扣减规则

local function buy(actor)
    STOCK = STOCK - 1               -- 不验余量，负库存超卖
    giveitem(actor, "裁决之杖", 1, 0, "限量抢购")
end

local STOCK = 1000
local function buy(actor)
    if STOCK <= 0 then
        sendmsg(actor, 1, "已售罄")
        return
    end
    STOCK = STOCK - 1
    giveitem(actor, "裁决之杖", 1, 0, "限量抢购")
    if STOCK == 0 then
        sendcentermsg("限量商品已售罄！")
    end
end