I saw this for £7.99 in the Wigan GAME store last week but didn't buy it because it was pretty bashed. In Bury's GAME store today, I saw a copy marked down as £19.99 (the old price), but it scanned through as £7.99 so it seems to be a nationwide deal, regardless of what the price tag says.
I don't really use strategy guides in games, but this is a really nice hardback book with some cool lithographs, hard to pass up for less than a tenner.
Also, this is my first deal. Be nice :)