Let's see, where I went to college, I could rent a 3 bedroom 2 bathroom house for $900 a month...split that 3 ways, that's $300 a person, plus say like $100 for utilities and stuff. So that's $400...then let's say another $100 for food, $50 for gas, and that's still like $500 extra (after taxes) to spend on a car payment, more food/beer, misc....it's not hard, really.
But then you have other areas like NYC where you have to pay like 1600 for a 1 bedroom and you have to pay city, state and federal taxes so that 340 a week turns into like 220 a week.
In that case, I'd hope that NYC businesses would be forced to offer better wages to employees, or face a shortage in labor as people seek employment in a more feasible place to live.