Is there a new computer on the horizon?

I'll explain this very briefly to you. A guy in my DT class managed to make his dream computer for £300 and he enthusiastically railled that it was easy to get an amazing computer for that price. I have £500 floating in my bank account, unused through steady accumulation. Therefore I made the decision to run headlong into this as a new project. The following are the results of an internet hunt for components which all work together and hopefully don't cost too much as a new computer to put in my room. I haven't included a monitor because they cost loads and I'm over budget already. Here's what I found:

Components:

Graphics card: Sapphire Radeon HD 4870
RAM: Corsair Dominator DDR2 (4x1Gb)
Hard Drive: Seagate Barracuda 7200.11

Motherboard: ASUS P5Q3 Deluxe

Sound Card: Creative sound blaster Audigy

Speakers: Creative GigaWorks HD50

CPU: Intel Pentinum 4

Optical Drive: Pioneer BDC-202 Blu-Ray SATA Drive

Power Supply Unit: Antec EA 650

Case: Antec Twelve Hundred

Mouse Mat: Razer Goliath Control

Keyboard: Razer Lycosa

Mouse: Razer Deathadder

Costing:

Graphics card: £196.35
RAM: £50.95
Hard Drive: £51.11

Motherboard: £153.93

Sound Card: £30

Speakers: £100

CPU: £57.25

Optical Drive: £84.54

Power Supply Unit: £70.11

Case: £121.83

Mouse Mat: £ 11.17

Keyboard: £44.70

Mouse: £33.52

Total: £1,005.46

[I really, really want to play Crysis or Half-Life: Lost Coast]

[Plus I want a soft plushy chair to watch Blu-Ray movies in]