Xbox 360 Hard Drive Storage 250/320GB Phat Console

Hey guys, I'm trying to find a hard drive replacement for my old Xbox 360 phat console that is either 250gb/320gb (whichever is cheaper).
If I look on Ebay I can find a 320GB for around $60. I'd rather a 250GB but not many people are selling it and it's around the same price anyway.
Does anyone know of a better place to find these for a cheap(er) price?