One of the record companies’ major beefs with Apple is that Apple won’t let them charge variable prices. One of the chief reasons that Amazon was able to get permission to sell non-DRM MP3 files is because they do in fact use variable pricing. That means, of course, that Amazon can offer things on sale from time to time. Today I picked up Weezer’s Pinkerton for $2 and Led Zeppelin’s Mothership for $5– significantly cheaper than buying the album, or the individual tracks, from iTunes. The only way I know of to get notified of these sales is to sign up for Amazon’s MP3 newsletter (or check slickdeals.net daily, which is what I do).