Fair price for 10x15 cm (4x6 in) prints?

Hey guys, any idea how much is the fair price per 10x15 cm (4x6 in) print? Some guy from Sweden wants to buy a few of my photos..

Any help would be great.

One option you could do is get yourself an account at a online Swedish pharmacy or photo store. I am sure the Swede can recommend a store nearby to him. Upload the photo(s), send the confirmation E-mail to the Swede and he can collect and pay them at a nearby store of choise. That way you avoid shipping costs and you run no risk that you pay for printing without getting a refund. Of course doing it this way you can not add a profit margin, should you wish to make money out of it.

I'm looking to make a bit of profit off of it.