Hi. The balance you see is only an estimate, when you request payment, a document is generated with all the details, including transaction fee and tax withholding, as well as refunds or additional charges.
In my personal experience, that balance tends to be smaller than the actual final value, but as I say, you will be able to see the details when the payment is generated.
If it serves as a guide, the fee for each transaction is usually between 0.5 and 1 dollar (NOTE: It is only a reference value, since it depends on the payment method used and the value of the game), you must deduct the Itch percentage (10 % by default) and tax withholding for transactions made from the USA. If it is the first time you request a payment, you have an additional charge of 3 dollars for the validation of your tax interview.