As above, noticed on the normal games shelves Boom Blox for the Wii priced and stickered at £10. next nearest I can is Amazon at around £15.
Reviews of the game seem good.
My friend bought one yesterday and I went in and bought one today. Staff said they had plenty left.
Only caveat is that this may be store specific but was a good bargain when they are going for over a tenner second hand on the well known auction site so it's worth a punt if you can find it.
This was at Sainsburys, Whitley Bay.