AKG Y50 headphones. Normally sell for circa £70 (see Amazon website). The black colour version will be in stock at Amazon from 8 December for £49.99.
These headphones have been well reviewed and are the What Hi-Fi 2014 product of the yearhttp://www.whathifi.com/akg/y50/review
I have tried them myself and the build quality is probably equal to that of headphones costing twice the price. Sound quality is also excellent.
The black version is far more "conservative" than the red, yellow and blue versions that have AKG plastered in large white type over the earphones.