I"m a bit late on this one, but I bought a new computer a few months ago. A desk-top, mind, but for just over £500 I got 4mb RAM, I5 3.30 GB processor and a massive 21.5 inch monitor!
I got it from a small company called ARBICO in South London because it came top of all the surveys.
It"s amazing what you can get for £500. Why does anyone spend more?