cheapest I can see anywhere right now. Its been out of stock for ages and then comes back and is £2 quid cheaper... Result!!!
EDIT: I've now found it on Tesco for £17.97 delivered. In stock now but don't know how long for. Here's the direct link:http://www.tesco.com/entertainment/product.aspx?R=824074
Thank you for the votes and Reps.