This fee is charged by your credit card issuing bank, based on the terms in your credit card agreement. This fee is not charged by AbeBooks and AbeBooks cannot refund it.
The most common reason international transaction fees are charged is because you are purchasing merchandise from a vendor located outside of your country. However, some credit cards issuers also charge the fee for transactions in a foreign currency.
You can avoid international transaction fees by limiting your purchases to booksellers within your own country (or within the European Union, if you live in the EU), or by limiting your purchases to your domestic currency. Be sure to check with your card-issuing bank to confirm under which circumstances they charge the fees.
Alternatively, there may be credit cards available to you that do not charge international transaction fees.