I saw in my local Sainsbury's (Warlingham, surrey), the wii just dance game for £19 and they had quite a few in stock, roughly 6. This is a great price considering its actually in store and available! Please note, I am not sure if this is nationwide. I just happened to see it in my local store and thought I'd post it in case anyone else is interested and looks in their local store.
This is a brilliant game to play with mates or even alone if you want to burn calories. It makes you sweat hell of a lot more than the wii fit! Its such great fun, def a must have game for your wii collection!