The shorted crypto transfers and fluctuations issues were time and energy consuming in the past, from today, all Bitcoin orders will be quoted in BTC currency instead of USD.
The assistants will give you the Bitcoin value with several digits and you will have to pay the exact amount required.
The payments are allowed and hash to be sent within 12 hours, if the buyer didn't have the Bitcoins ready within 12 hours, he will need to ask for an updated quotation of corresponding Bitcoin value of his order.
If he send shorted money, like less than the Bitcoin amount required, or send after more than 12 hours, and some fluctuation happened that we received less than what it should be received, the difference will be required to be paid in stable coin, and the amount won't be refundable.
If you want to avoid this restrictions of time, use stable coins like USDT or USDC.