I've put in all necessary components plus hard drive and optical drive and I'm nowhere near the budget, mainly because the difference won't be huge or can be made up via overclocking easily. Quad core, an 8800GTX or possibly 4gb Ram(would need Vista though) are about the only other things that are going to stretch the budget and depending on your uses might not be worth it.
Corsair HX 520W ATX2.2 Modular SLI Compliant PSU (CMPSU-520HXUK) £59.99
(£70.49) £59.99
(£70.49)
Lian-Li PC-7 PLUS Aluminium Midi-Tower Case - Black £49.99
(£58.74) £49.99
(£58.74)
Gigabyte GA_965P_DS3P (Socket 775) PCI-Express DDR2 Motherboard £74.99
(£88.11) £74.99
(£88.11)
EVGA GeForce 8800 GTS ACS3 SILENT 640MB GDDR3 HDTV/Dual DVI (PCI-Express) - Retail £224.99
(£264.36) £224.99
(£264.36)
Intel Core 2 Duo E6600 "LGA775 Conroe" 2.40GHz (1066FSB) - Retail £127.99
(£150.39) £127.99
(£150.39)
Western Digital Caviar SE16 320GB 3200AAKS SATA-II 16MB Cache - OEM £47.99
(£56.39) £47.99
(£56.39)
Samsung SH-183LBEBN 18x18 DVD±RW Dual Layer Serial ATA Lightscribe ReWriter (Black) - OEM £17.99
(£21.14) £17.99
(£21.14)
Noctua NH-U12F (Socket LGA775/754/939/940/AM2) Heatsink £30.99
(£36.41) £30.99
(£36.41)
Crucial Ballistix 2GB (2x1GB) DDR2 PC2-5300C3 667MHz Dual Channel Kit (BL2KIT12864AA663) £63.99
(£75.19) £63.99
(£75.19)
Sub Total : £698.91
Shipping cost assumes delivery to UK Mainland with:
City Link Parcel Next Day (Delivered Mon-Fri)
(This can be changed during checkout) Shipping : £10.95
Vat : £124.23
Total : £834.09