Overclockers have a 7970 for £329.99 for this week:
http://www.overclockers.co.uk/showproduct.php?prodid=GX-097-GI&groupid=701&catid=56&subcat=938
If you don't want to stretch for that, the 7950s can be had for £250 - £300 on overclockers, too.
Most of these cards come with Crysis 3 and...