The deal or no deal thing is a fucking con, like. The biggest box always goes in 2 rounds and it's heavily skewed so that if you lose the top box, you're very lucky if you get your stake back.
EDIT: I had a free fiver casino bet that I wanted to use on football, so I just opened the first round of boxes and took £5.38 that I was offered or whatever, I was certain I'd end up getting about a quid off it.