In HMV Cheltenham, these sumptuous cans were marked at £259.99, not blue crossed. Some other cheaper ones were blue crossed with a sign on the wall saying up to 40% off, including some Bose AC3s.
I thought I might as well give it a shot so i took these up as well as the Bose ones. The guy told me the Bose were only 20% off but for some reason these were going through at half price. Needless to say I jumped at it. He said it was a misprice on the national computer and they were only supposed to be 10% off. £260 seems about right online going by Google shopping.
Great review here - http://www.whathifi.com/review/momentum
£155.99 when I bought a pair today.