Wow, I thought this was a brilliant price as I dont think Ive seen it under 20 quid anywhere else! This is part of their Easter sale.
Just to clarify that this is a price for the game only, but Im sure most Guitar Hero fans have a plastic guitar laying around somewhere! This is also instore only, the website is quoting 17.98
I also saw a copy of GH Greatest Hits for the same price, and I also picked up a copy of Blood Bowl for £14.98 - also New.