Posted Pandemic Legacy a week ago for £40.60, but now found it even cheaper, at £36.95 it is by far the cheapest I've seen this game. Pandemic Legacy is a game about stopping a disease outbreak over a 12 month campaign where each month of game time new rules and modifications to the game will be made to surprise the player. Ranked the number one tabletop game of all time over at Boardgamegeek.com so you know it is something special. Both the red and blue boxed versions are available for this price (there is nothing different between the versions other than the colour of the box)
Also on offer at the lowest price I've seen it is Pandemic: Reign of Cthulhu for £30.95. If you liked the idea behind the original Pandemic game, but would prefer to play a modified version with cultists instead of infections and the ever present threat of the Old Ones then this might appeal to you.
In both cases use the code FORGOT at checkout to get the extra pound off to see these prices. Blue box and Reign of Cthulhu links in first comment.