The Amazon MP3 Store
offers downloads of select MP3 albums
each. That's tied with last week's mention and among the best such sales we've seen from Amazon, with many MP3 albums at the lowest prices we could find. Amazon MP3 Downloader is required.
A best bet is downloads of Rage Against the Machine's The Battle Of Los Angeles MP3 Album for $2.99. That's the lowest price we could find for this 12-track, DRM-free rap metal album, originally released in 1999. (iTunes and Google Play both charge $10.)