For those unable to pick one up at Sainsburys for £12:http://www.hotukdeals.com/item/587071/resident-evil-5-360-ps3-12-sainsbur
Asda are selling the PS3 version of the game for the same price, came back from my local Asda (Colindale) and saw it while looking at the games section.
Cannot confirm whether it is nationwide (it was actually ticketed and didn't have a reduced sticker on the case) and if it's also the same price for the Xbox 360 version.
Didn't pick one up myself for I'm waiting for the Gold/Alternative edition to come out.
Happy deal hunting!