I just went to Sainsbury in Hampton (St Clares) tonight. They had the nation wide promotion: PS3 160GB + 2 games for £199.99
I picked two "Fifa 12" games. The console plus the two games scanned at the till for £114.01, as they are deducted twice! If you sell the games (easy, in high demand), you can get a PS3 for about £50.
See picture of till receipt, clearly a mistake in the way the promotion is set up.
Update: reported by some people to work at other stores! Be quick before they correct it. Seems only to work with two "Fifa 12" games