拍卖行：出价越高手续费阶梯递增

-- 错误：单一比例，大额交易税负过低
local fee = price * 0.05

local TIERS = {
    {cap = 10000,  rate = 0.05},
    {cap = 100000, rate = 0.08},
    {cap = math.huge, rate = 0.12},
}
local function auctionFee(price)
    local fee, last = 0, 0
    for _, t in ipairs(TIERS) do
        if price > last then
            local seg = math.min(price, t.cap) - last
            fee = fee + seg * t.rate
            last = t.cap
        end
    end
    return math.floor(fee)
end
local p = getplayerbyname("auc01")
sendmsg(p, 1, auctionFee(150000))