Zavvi had it at £16.00, until they put it up in price for their 'sale'. I ordered from them at sixteen and have been waiting for their back order to come in for some days. I found this deal earlier when I was considering cancellation. However the Zavvi order has just moved to 'In Progress'... which is still not despatched but does not allow me to cancel.
Anyway, fifteen pounds seems like a bargain to me (if you are quidco registered).