This is a deal from both Sainsburys and PC world.
Firstly buy the game for the PS3 solus in Sainsburys for £10, then in PC World they have the PS2 version of Buzz with wired buzzers priced at £10, thing is that they scan at £5. The buzzers work perfectly with the PS3 version of the game and although they're wired, this is actually a positive as it means you don't have to continuously replace the batteries of the wireless ones.
Also you get the PS2 version of the game which you can either keep this and play it on your PS2/PS3 if it's backwards compatible or sell on.
note. this was easy for me as I did it at the Braehead, Glasgow stores where PC World and sainsburys are very near to each other