@SC

I would say its Mid to High end, I would personally consider it an entry level gaming system. this would be able to play all the latest games with 90% of the features enabled.

you could reduce this more by shopping around, note the £300 price tag without OS or Monitor, so if you wanted a Linux box and already had a decent monitor or KVM it would be very cheap for the specification, compared to off the shelf systems from like PC world or other main dealers like DEL.

If you were to Base a PC on the specifications that you have for the program, then its would be under £200, but it would be limmited as well as most of the parts would likely be second user, as the main PC buying market is pushing core duo and AMD's Phenom based products one could be hard pressed to find a single core P4 at 2.2ghz let alone a 462 motherboard of that specification out side of ebay.