There are lots of places to get music....
And a lot depends on the types of music you play.
For example, if you are willing to invest a lot of time, DigiWaxx is a good source, but you have to listen to each track, provide feedback and then you can download it.
If you want lots of tracks, with most of them being top tracks, check out Promo Only Pool (what I use), but there are other services as well. RPM, TM Century's Prime Cuts, etc.
Side note: Promo Only Pool allows you to download both Apple Lossless and MP3. Apple Lossless isn't supported for playback in Cross - yet.
So if you go this way, get the MP3 versions.
There are lots of cheap pools but the quality tends to be lackluster at best. For example, much of the original video I got from VideoToolz/8th Wonder are flawed or have other issues. They play back 'ok' in all but the rarest of cases, but overall I'm frustrated in the quality.
Of course, you can also go a bit old school. I hit up pawn shops and used CD stores for stuff all the time. I've gotten some GREAT deals that way.
c00l People MV Society 
