Using this voucher code from vouchercodes.co.uk:
£10 of £150 spend VCUK811
Usual price 149.98 just add something really cheap to the your order like a cable, batteries or CDRs to tip it over the £150 mark, type in the code, and hey presto a cheap 5850.
Code expires on Monday 6th December apparently.
Taking 3 enormous steps towards realistic gaming, the XFX Radeon HD 5850 with Eyefinity technology, gives the first-ever wrap-around in-picture experience to fully immerse yourself in the game, or maximize your productivity at work. Additionally, with ATI Stream technology, boost your systems performance by offloading tasks originally sent to your CPU, to your GPU and max out your settings with the first ever full support for Microsoft Directx 11.