In the past, I have downloaded MP3s from a couple of sites based here in the good ol' USA. With one, their selection wasn't very extensive (BMG). With the other, I had some bad experiences (seemed their system would tag music that I ripped from CDs as protected, etc.) (Napster). At both sites, each MP3 was $0.99.
But, some time ago, I was given a link to http://www.gomusic.ru.
Their library seems to be larger than either of the above two. They haven't tagged any of my pre-existing music. And, each song is only $0.19. With full CDs being an average of only $1.50, to me it's a damn good deal. (The only thing that some bigotted Americans might consider a drawback, the site is based in Russia, thus the ".ru")
Oh, they also have quick response times on tech support, where Napster never responded to queries.