Help me find cheap 7200rpm hard drives for webserver raid/mirroring

[Soulkeeper]

all I need is like 15 or 20gb hard drives
i wanna get 4 drives and set them up in some kinda striping/mirroring config with my raid card

any good places to pick up older/smaller drives for like 30 bucks ??

i don't care if they are refurbished or anything as long as the work and don't make weird noises or go out on me in a few weeks

thanks