I've just purchased the iCarly Wii game for my 8 year old daughter for Christmas. The cheapest I could find this was for £9.19 on both Play & Amazon. I opted to purchase from Play so I could also get Quidco. I hope this helps other mums with big iCarly fans! :-)
Amazon link : http://www.amazon.co.uk/ACTIVISION-iCarly-Wii/dp/B002BH3VQA/ref=sr_1_1?ie=UTF8&s=videogames&qid=1288869499&sr=8-1
Also, just to add, I hadn't spotted this before until today but iCarly 2 Wii game is due to be released on 19th November and is available for pre-order at just £14.99 from Play.com.