Here's another one I'd forgotten about. They have both CDs and downloads, including individual tracks.

All Celtic Music.com


They're based in Glasgow, so maybe they'll have more of the more locally known artists that you're looking for. Just curious, could you give some artist names so we can get an idea of what you're after?

Their downloads are just a miniscule subset of their collection - I think they're just there to whet your appetite.

Here's an example I was looking for today - the group Cran - a couple of songs from the album "The Lover's Ghost".

Another recent example -   Michael O'Suilleabhain, tracks from the album "Becoming".   Also tracks from his album Oilean/Island. Amazon has the Oilean/Island CD for $94.00 (apparently because it's out of print).   

As I was explaining above, one advantage of electronic distribution is that nothing ever has to go out of print.