I was looking for a low priced Sennheiser PX100 for a while, and here it is. Usually sold around £30 so it's a real bargain for the price tag. One of the best open headphones in this price range, with practical foldable headband.
You can find a review right here: http://www.devhardware.com/c/a/PC-Speakers/Sennheiser-PX100/
+Use voucher code "BACKFORGOOD" to get the price shown above+