i've found ebay to be consistently the best source of cheap CDs and DVDs..

..just gotta check for your wants list frequently..
and be prepared to accept miniscule risk of buying worldwide
and waiting for delivery..
or occasional broad interpretations of the words
'mint' 'unplayed' 'as new'..

so far i've managed to locate nearly every CD i want..
and buy cheaper than any 'discount' web stores..
and certainly far cheaper than 'specialist' internet CD stores..

this includes saving considerable amounts on supposedly 'rare'
collectors CDs..

BTW much respect to US ebay sellers who charge fair priced combined cost shipping for 2 CDs or more..
and then, without being asked, do whats needed to help UK customers avoid any import tax/VAT surcharges..