Hi, Ameoba records and Rasputin records both on the infamous Telegraph have a very wide selection of quality used cds and even their brand new cds are very reasonable at around 12-14 bucks (around 8 bucks less than wherehouse)! Ameoba has a good celtic section and folk section. You can find pretty much anything there (and what you can't find, they can order for you for pretty cheap). I wish you good hunting!