Ebay is another option. I just bought Adobe Photoshop 8.0 CS + Adobe Photoalbum 2.01 for $19.46 . I was the only bidder.
I still can't believe that. Even used, noone would sell an original copy at that price. Since your post I've been looking at several offers of Photoshop CS, and I've found sellers who are selling multiple copies very cheap with few bids. This is fairly obvious to me that these are illegal bootleg copies, and can't be registered with Adobe, even if their customers are satisfied. Alas, too good to be true... 



