I gave it a shot. Came out at $370 & change for a low end system. Intel Celeron duel core, Biostar micro atx lga775 mobo, 4GB DDR2 800, 1GB GeForce GTS 450 (Fermi/DX11) ,generic case with a 420 watt PS, 500GB Seagate HDD & a Samsung DVD burner.
Can't claim to be the best at building systems, but I gave it a go. All available through Newegg. Did I leave anything out?