The Age of Misrule Omnibus has sold out in the UK, although copies might still be available at retailer level. The Omnibus was always intended to be a short-term special edition, but the publisher was overwhelmed by the initial demand.
The story will still be available in the individual volumes – World’s End, Darkest Hour and Always Forever. World’s End has just gone into its fifth printing so there should be loads of copies around.
When we had it in the store I worked for it very rarely stayed on the shelf for long.
Admittedly, that also ma yhave soemthign to do with the fact I recomended it to pretty much everyone :p