The Amazon MP3 Store offers downloads of U2's The Joshua Tree (Remastered) MP3 Album (pictured) for $4.99. That's the best price we could find for this 11-track, DRM-free rock album, originally released in 1987. (iTunes charges $9.99.) Amazon MP3 Downloader is required.

Of note, the Amazon MP3 store also offers downloads of U2's The Best Of 1980 - 1990 MP3 Album for $5.99. That's the best price we could find for this 10-track, DRM-free rock album, originally released in 1998. (iTunes charges $7.99.)