Here we go again!
Was in Sainsbury's earlier and seen that the Guitar Hero World Tour with Guitar is reduced to £49.97, £30 off their usual price. Not all the packs will be stickered with the new price, but they will scan at £49.97.
Next cheapest I've found on this is £54.99 at amazon.
I know for sure its on the PS3 and 360, but 99% certain its on the Wii as well!
Hope this is of some use to people.