I was just wondering how much I should sell my PC for. Its about a year old.

This is my rough spec:

Intel 2.4ghz dual core
Nvida 8800gt graphics card
4gb memory
1000w psu
250gb hard drive

I'm also using a 22" lcd monitor, gaming keyboard and mouse total rrp £120 if someone could give me a rough idea. I've spent about 1400 on this system and would be looking for about half of it on resale but I am not sure about prices. Thanks

You could advertise on EBay at the price you would expect. That will tell you soon enough when you start getting offers.