Tigerdirect has eMachines W5243 Refurbished AMD Athlon 64 3800+ Desktop Computer for $199.99, use live.com cashback for $25 back, + shipping
Spec: AMD Athlon 64 3800+ 2.4GHz (HT), 1GB DDR2, 250GB SATA II HDD, DVD±RW Dual-Layer, NVIDIA® GeForce® 6100 chipset, Windows Vista Home Premium
90 days warranty, spec page