In California 40% of the population makes less than $36,000 a year and 80% makes less than $99,000 a year.
In New Jersey, 40% of the population makes less than $41,000 a year and 80% makes less than $116,000 a year.
In Connecticut, 40% of the population makes less than $44,000 a year and 80% make less than $121,000 a year.
In Washington DC, 40% of the population makes less than $33,000 a year and 80% makes less than $97,000 a year.

If there are so many people living in those expensive areas on less than $45,000 a year, there is no amount of living expenses that suddenly make those in the top 20% into part of the "middle".

ITEP has data for states, but not for metro areas http://www.itepnet.org/state_reports/whopaysfactsheets.php

But in places like Jersey and Conn, probably 80% of the population is in the metro area. Even in Manhattan, many, many people are living on much less than $150,000 a year, especially for one worker.