BlahDVD is selling "Fishing Master" for the Nintendo Wii for £17.99 (inc Del.)
You can get cashback on top of this from the usual sites (e.g. 8% Quidco, making it just £16.55)
Next best price seems to be £23.99 from HMV.
Fishing Master is the first Arcade style fishing game to hit the Nintendo Wii. Choose from an array of different types of bait. Cast your line with the Wii Remote. And start reeling inover 100 fish with your Nunchuck? in your sole quest to become a Fishing Master. Fishing Master is fishing fun for the whole family! Test your fishing skills in your quest to become a Fishing Master in over 30 fishing tournaments in single player mode. Fish Encyclopedia - Learn more than just fishing techniques. A true Fishing Master learns about every fish you catch in the game. ESRB Rated E for Everyone