bandit.fm - download albums for $6.85 each, or less.
So $120 worth of music for $47.97
Albums costs seem to vary from under $10 to around $17. For example the Glee Cast Madonna album - 7 tracks - costs $9. Individual tracks generally cost around $1.69 each but can be cheaper.
If you purchase albums with only a few tracks on them, sometimes it's better to buy the tracks individually rather than the album - eg if you like Brian Eno (which I do) then entire albums "Neroli" and "Thursday Afternoon" will only cost you $1.69 each. Many classical albums also only have a few tracks or perhaps have "filler" tracks you're not interested in, so can be quite cheap.
Let's take the "worst case" though - $17 for an album means that for your $47.97 outlay you could get at least seven albums. That's $6.85 per album. All are DRM free mp3 files, 256kbps or better.
Cons - Selection is nowhere near as large as iTunes, (if you have an ipod) it's a manual process to load into your iPod/music library unlike itunes, you don't appear to be able to re-download tracks if you lose them, and credit not used in one month do not roll over to the next. Oh, and the site is flash dependant - so don't bother trying to browse it with the iPhone/touch!
On the pro side, this is pretty cheap if there is music there you like, and the quality is high & the files can be used on pretty much anything. In general what I'd probably suggest would be setup an account (to do it is free, and in fact there are a number of "special deals" available (such as via some twisties/chip packets and/or via Qantas fflyer) for free credit that you can use to trial the service. If you like it and/or there are at least seven albums you'd like to buy then this is a good way of getting them for a discount.