I agree that www.emusic.com
is a fantastic resource for legal but inexpensive downloads. I have been a member for 3 years, and have barely scratched the surface of the tons and tons of electronic music they add daily. If you are a fan of any variation of electronic music you should check it out - and it's not just indies you have never heard of either - there are plenty of well-known artists too. I don't know how other subscription services do it, but with emusic you have a profile with a list of everything you have ever downloaded so that you can go back and re-download anything you have previously downloaded, just in case you accidentally delete it from your hard drive.
Another great resource for electronic tracks is www.download.com
. They have every genre of music, but the commercial tracks for mainstream pop and rock type stuff are often for streaming only, not just for downloading. With electronic music, the possibilities are wide open - you can listen to the compositions of people from all over the world, many of whom are just regular joes who create some of the most amazing music I've ever heard.
There tends to be a lot of free electronic stuff to be had, usually on the websites of the people writing it. It's not so hard to find if you google around.