One of the issues with selling outside the United States is in dealing with foreign currency. First, you have to convert it to U.S. dollars. (How many lira to the dollar today?) Then you have to receive it in a form that is both secure and trusted. (Do you trust a personal check drawn on a small Spanish bank?) Then you have to find a way to deposit those funds and convert them to U.S. dollars. (Does your bank handle foreign deposits?)
The currency issue is simplified somewhat when you specify bidding and payment in U.S. funds only. This puts the onus of currency conversion on the buyer, which is a plus.
The payment process can be further simplified when the buyer pays by credit card or, even better, by PayPal. PayPal is now active in 45 countries (including the United States) and can handle all the payment, conversion, and deposit functions for you.