(I will be upgrading the GPU in time by the way)
Case & PSU
Coolermaster K380 and Coolermaster elite 500W PSU
http://www.ebuyer.com/442065-coolermaster-k380-and-elite-500w-psu-rc-k380-kwp500
£54.62
RAM
Corsair 8GB (2 x 4GB) DDR3 1600mhz vengeance
£55.00
Mobo
Gigabyte GA-970A-DS3
http://www.ebuyer.com/349910-gigabyte-ga-970a-ds3-socket-am3-7-1-channel-audio-atx-motherboard-ga-970a-ds3
£52.77
GPU
Already got - Radeon HD 6670 1GB DDR3
£0.00
CPU
AMD FX 6300 3.5Ghz
http://www.scan.co.uk/products/amd-fx-6300-black-edition-vishera-six-core-s-am3plus-35ghz-14mb-total-cache-95w-retail
£88.36
HDD
WD Blue 1TB
http://www.ebuyer.com/393482-wd-1tb-blue-desktop-drive-wd10ezex
£50.20
OS:
http://www.ebuyer.com/259863-microsoft-windows-7-home-premium-w-sp1-licence-and-media-1-gfc-02050?utm_source=google&utm_medium=products&gclid=CKyw7smbibgCFfMQtAodCVYAxg
£68.99
Monitor:
Already got
£0.00
Total
£369.74
Case & PSU
Coolermaster K380 and Coolermaster elite 500W PSU
http://www.ebuyer.com/442065-coolermaster-k380-and-elite-500w-psu-rc-k380-kwp500
£54.62
RAM
Corsair 8GB (2 x 4GB) DDR3 1600mhz vengeance
£55.00
Mobo
Gigabyte GA-970A-DS3
http://www.ebuyer.com/349910-gigabyte-ga-970a-ds3-socket-am3-7-1-channel-audio-atx-motherboard-ga-970a-ds3
£52.77
GPU
Already got - Radeon HD 6670 1GB DDR3
£0.00
CPU
AMD FX 6300 3.5Ghz
http://www.scan.co.uk/products/amd-fx-6300-black-edition-vishera-six-core-s-am3plus-35ghz-14mb-total-cache-95w-retail
£88.36
HDD
WD Blue 1TB
http://www.ebuyer.com/393482-wd-1tb-blue-desktop-drive-wd10ezex
£50.20
OS:
http://www.ebuyer.com/259863-microsoft-windows-7-home-premium-w-sp1-licence-and-media-1-gfc-02050?utm_source=google&utm_medium=products&gclid=CKyw7smbibgCFfMQtAodCVYAxg
£68.99
Monitor:
Already got
£0.00
Total
£369.74