eBay.com has the refurbished Dell P4 PC Desktop Computer for $144.99. This system ships for Free, and it features:

• Intel P4 2.8 GHz CPU 
• 80 GB SATA Hard Drive
• CD-RW/DVD Combo Optical Drive
• 1 PCI-e Expansion slot (For adding Faster high end video cards)
• 1 PCI Expansion Slots for add ons
• Integrated Realtek AC97 Audio with premium internal speaker
• Integrated PCI-E Broadcom Netxtreme Gigabit (10/100/1000) Ethernet NIC
• 8 USB 2.0 High Speed Ports (2 in front, 6 in back)
• 1 VGA Port
• 1 serial
• 1 parallel
• USB Keyboard and Mouse interface