Will I pay any fees or tax on top of the price?

Before you confirm a payment, the confirmation screen shows the price and the total you'll pay.

If tax applies, it's listed as a separate line with its rate. The same goes for a processing fee, which is shown as Processing Fee. If neither line appears, you pay the price shown.

Your bank may charge its own fees, for example for paying in US dollars from a card in another currency. See What currency does PlayHouse use?