IT salaries in high cost areas

I am finding that the same job pays the same amount of money no matter where in the country the job is located, and I’m finding that for contract work that companies aren’t even willing to pay for per diem when you qualify under IRS regulations for maintaining two residences.

Is there any way you can use the cost of an area to leverage an adequate salary? To give an example if you work in area A for 80K it costs $185 K to live at the same rate in area B – vise versa – that 80 K salary K in area B is equivalent to about 30 K in area A – so if you live in area A you might be better off being a janitor in area A than a high level IT employee in area B.