Bring every cost together
How much USDT will this cost?
Use the merchant quote and confirmed fees. Leave unknown fees blank; they are not treated as zero.
Which costs are easy to miss?
Fixed fees on small purchases
The same fixed transfer fee can take a larger share of a small top-up. Compare the full amount before deciding.
Counting a transfer fee twice
If an exchange withdrawal fee already covers the transfer, do not add that network cost again. Follow your actual payment route.
Face value is not the payment amount
A product face value in local currency is not its USDT quote. Merchant pricing, conversion and additional fees affect the total.