Amazon (I buy used from there, but be careful because each seller you buy from the shipping and handeling fess will increase)
Warehouse Music (I go to to their store and search, usually buying used which is around 3.99-9.99)
Walmart (always pretty cheap)
Best Buy and Circuit City (when new releases are available, usually they are sold at a very low price 7.99- 9.99)
Also try Circuit City when they have their really big sales for cd which is usually 2-3 times a year. Every cd ranging from 9.99 - 13.99 is 9.99. Those sales usually coincide with holiday sales (i.e. Memorial Day, Christmas).
