On Buy/Sell, you can only set market orders and there is no execution fee. There is a spread, which can range from 0.1% to 6.0% depending on the volatility and liquidity in the overall crypto market.
What is the reference total?
The reference total shows you the average cost of your purchase or sale using the average between the current buy and sell price. The reference total is only for your reference and will not reflect the actual amount of the transaction.
NOTE: The reference total is NOT the amount the transaction will be for.