Amazon Mp3 everyday has cd's (in mp3 format) for under 5 bucks. I will try my hardest to keep you updated so you can get a great deal. Right Now:
Broken Social Scene - You Forget it in the People is $ 1.99 no gimmicks. Download HERE. I got Led Zep IV the other day for the same price. Check this website for daily updates. Like I said I will try to update you.
Also, Echo & the Bunnymen is $4.99 HERE.
Fleet Foxes is only 7.99.