One of the things engineers (who build things) say is:
Good, Fast, Cheap: pick any two
That is, if you want the engineer to build something for you, you can have it done quickly and very good, but it will cost you. If you can only afford cheap, then it will either be done quickly, but not so good, or slowly and better.
Being a postdoc (or even faculty) is similar:
High-cost city (Boston, NYC, SF), Lifestyle, Post-doc position: pick any two
Money goes a lot further in the heartland of America, but that's not New York or San Francisco or Seattle. The NIH scale for postdocs is a living wage, above the median for a family of four in these areas. It just may not be the living you had in mind.