I just picked up a Power Mac G4 (Digital Audio) with dual 1.8Ghz processor, 1.5GB RAM, ATI Radeon 9800 and DVDRW for $100.00 flat, local pickup. This is almost perfect for today's supported hardware, with the exception of the Radeon 9800 not having 3D support yet.
Damn that is sweet for a hundred bucks. You lucky sod.