Dvd.co.uk are selling "Glory Days 2" for the Nintendo DS for £9.99 (inc Del.)
You can get cashback through the usual sites (e.g. 4% Quidco, making it £9.59)
The next best price seems to be £14.93 from The Hut.
Glory Days 2 DS - Brotherhood of Men delivers immersive and compelling multiplayer options where friends can compete against each other, which is a special orientation by the developer, ODenis Studio. Epic multiplaying 2 player competition, along with huge 4 cooperative play, allows individuals to show off their skills as well as working as a team. Distinct objectives can be assigned to each player from controlling and saving civilians in a helicopter, whilst a friend controls air space in a plane, to form the perfect alliance of skills.