Hang on, Mr G. Didn't you recently upgrade your PC? And you found a place selling BF3 LE for only £25???!!
W00t. I know what I would do!
Load up Unreal Tournament and get used to the mouse/keyboard again. You'll soon get the hang of it and rediscover why it's so much better than using a control pad.
However, I am sure the console is king when it comes to minimising hassle. They are already talking about a day one patch even for the console but higher texture downloads for the PC.
Bigger maps for PC though. Swings and roundabouts I guess. Might check ASDA out myself though I believe Amazon (where I have been pre-ordered from since Feb) should price match that. I shall have to go see for myself.