Hi I'm looking for a temporary merchant account somewhere, where I can charge a mastercard from an international buyer just a one time deal maybe. I tried paypal but they don't allow the country the card is from.

Welcome to the forums PCcustoms!

You might try ikobo for something like this. I cannot remember if they have the ability to charge only Visa right now or if they recieved the ability for MasterCard once again. It might take a little to get your money. Might be easier in the long run to request a wire transfer