Where to find reasonably priced 2.5" hard drive for old Powerbook 3400c?

The hard drive in my good old 3400c work horse just died on me, and aside from ebay (which I don't really feel comfortable buying hard drives on) I have no idea where to get a 2-5GB 2.5" drive to replace the old one. I know I can pickup a 40GB or higher drive at a local computer store for about $80, but I don't really want to spend that much, as I would never need anywhere near that much room on the 3400. Is there a reliable place to find smaller drives, or am I stuck buying a new huge one? Thanks for any input!