Right now I pay about 2 or 3 bucks for an album's WAV files. I don't think it's going to get cheaper than that. The buy,rip,& sell method. Totally legal too.
Sometimes it's cheaper depending on how fast I can "turn" the disc reselling it and of course the demand.
Any CD is like a share of stock. It's only worth what someone is willing to pay for it at any given moment. Record companies still don't get "pricing" and they never will.