The Hut are selling "Super Mario 64" for the Nintendo DS for £9.93 (inc Del.)
You can get cashback through the usual sites (e.g. 10% Quidco, until midnight 26th (5% normally), making it £8.94)
£14.93 is the next best price, from Asda.
Tap into a New World.
Super Mario 64 has arrived for the Nintendo DS with all-new characters, courses, game modes and challenges! Play as Mario, Yoshi, Luigi and even Wario. Each has a different set of moves! Recover all 150 Power Stars - 30 more than the original game. Battle up to 3 friends in Wireless Versus Mode as you run and punch each other in pursuit of Stars. Try your hand (or styles!) at tons of new touch-sensitive mini-games.