www.allofmp3.com (Score 5, Informative)

The fine folks over at Allofmp3.com will sell you MP3s for a wide variety of artists. They don't seem to care what country your're in. As far as being legit, they say that they're registered with the Russian copyright authority and that they're authorized to sell what they're offering. I haven't heard about any independant verification of that, though.