You can buy Medieval Games for the Nintendo Wii for only £7.99 @ Amazon. That includes free super saver delivery.
Note that it is also £7.99 at Game, so you can choose your preffered retailer. The next available price online seems to be £12 @ HMV, so a bit of a difference there.
To be honest, this game received some mediocre reviews, with a score of only 6.8/10 on Metacritic. But it looks like the kind of game that might be good to whip out when you have a few friends round for drinkies.