I took my mario kart to trade into HMV today to get Mario Galaxy 2 for £4.99 and they refused because I didn't have the outer box for the wheel.
I took it 20 yards away to GAME and asked if they would match the deal. They said they wouldn't but scanned it anyway and it came up at £33!! leaving £4.99 to pay for Mario Galaxy 2 (£37.99 on the shelf).
I even got a money box too.
I'm assuming the deal will be nationwide.