Peter recommended this book a while ago on this forum and while I was in London last weekend I spotted a few cheap (under £10) copies in a bookshop on Charing Cross Road. It's a small shop mid-way between Foyles and Motorbooks (my usual itinerary) I think it's called Lovejoys. They have quite a good selection of military stuff, all remaindered.
Good find... I paid considerably more for my copy some years ago. Incidentally, it's a far better buy than the companion Verdun book by the same author.