One of the aspects of contract law, at least in my country, is that a contract is - in principle - supposed to result from a more or less equal bargaining procedure. Having an extremely strong bargaining position, and jamming it up to the hilt in someone's chest, is grounds for the contract to be held invalid here. It's called undue influence.

I believe there was a case a few years back where it was even specifically held that this invalidated a mobile phone contract because the woman couldn't predict the future as well as the phone company.