CEX have Terminator Salvation the Directors Cut: T-600 Special Edition instore for £12.
They had loads of copies in Totenham Court Road Branch, which all seem to be new.
It comes in an awesome 3D skull case. I believe these were only ever sold in HMV (perhaps CeX bought their unsold stock?) - cex seemed to have priced them up the same as the standard version (which would not be the directors cut with all the special features and not in the special 3d case).
They also had the two disk special edition DVD in the same skull case for £7. Also a bargain!