I've been after a pair of these for a while, but couldn't justify the price. They are on the Oakley website at £165 and I found a variety of sizes in TK Maxx in Bangor (NI).
I've seen them in TK Maxx in Belfast at £60, but for £30, they are a STEAL!!
The only issue was that I had to buy a plastic bag to put them in!!!
I don't know if it a National offer, but well worth checking out!!!
(I'm a size 11.5 and the U.S. 12 fitted perfectly. The store had at least 6 pairs in stock and they were priced with the red adjusted price sticker on the lower Clearance shelves)