Unless you're an internet savy eBay user, you may have trouble finding some of the more obscure CD's out there. My wife likes broadway music, and was looking for a CD she couldn't even find on eBay for less than $30.
But sure enough, after calling around she found it here. While they DO have a selection of more recent titles, those are prices so high that for a buck or two more, you could get them new at Wal-mart.
But their older titles are very reasonably priced, and you can listen to them in the store if you want.