I saw The Vampire Diaries 1+2 (Awakening and Struggle) for only £3 in Asda. I've been to both the Colindale and Wembley stores and they have a few of them there - so think it's nationwide. I had one of these world book day £1 book tokens they're giving out in the schools and so got the book for only £2.
Asda is also selling the Vampire Diaries (Fury and Reunion) for £4 in Asda - so £3 with another book token.
Hope this helps. And they are a great read for any Vamp lovers out there!