Potentially both parties may pay fees, each to their respective bank.
In other words the person paying is responsible for any fees charged by his bank while the recipient is responsible for any fees charged by the receiving bank.
When you sell something you set the price of that item or service. If someone wants to pay you in a way that incurs fees, they should pay those fees. But you need to specify that to your customer up front.
Both the sending and receiving banks will usually charge a fee to process a wire transfer. In addition, they may also be a currency conversion fee (typically 1%). You need to check with your bank to find out what your fees will be, and you can then ask your customer to pay your fees, or not.