I agree with CF re price. I recondition and resell PCs fairly regularly, and this is typical for a four or five year old machine:
Processor: Intel Pentium dual core E2180 2.0GHz
RAM: 4GB DDR2 (all slots are full)
Graphics: nVidia GeForce 7100
NIC: nVidia nForce
Sound: On-board high definition
Hard disk: 500GB SATA (room for four more SATA drives and 2 IDE drives)
Optical disk: ASUS DVD-RW
Floppy disk: 3.5” 1.44MB
Front panel: 2 x USB 2, Audio (mic & speakers, perfect for headset)
Back panel: PS/2 keyboard, PS/2 mouse, 4 x USB 2, Ethernet port, Audio
£100 + VAT, £20 UK delivery