Are postdoc salaries in the USA adjusted for cost of living? I'm a life sciences Ph.D. student preparing over the next few months to begin applying for a postdoctoral fellowship. Several of my potential advisors are on the coasts--California, Boston, Seattle--where the cost of living is quite high. Others are in the Midwest where the cost of living is much lower. I've lived a lot of places myself, so for the sake of argument we can assume I'd be equally happy moving to any of these places.

Although I don't want money to be a factor in this decision, I do have a wife and children and (insert salary here: $45,000 for example) allows a much different standard of living in the Midwest than Boston or Long Island. For those of you who received multiple postdoc offers--is this something that they take into account when setting your salary, or can I expect more or less flat offers across the nation?
There is a wide variety in the range of post-doc salaries. In the biomedical sciences, the NIH's salary guidelines hold sway, as the NIH is the largest source of funding for such positions. So there's relatively little cost-of-living adjustments. 

However, I think many institutes set their own scale according to "what the market will bear." Popular schools like MIT could pay somewhat less and still be competitive because of the "prestige factor."