[michaelochurch]

If you're comparing cities to cities (e.g. Chicago vs. SF, Minneapolis vs. Seattle) then I'd say that it's closer to 65k than 30k to get an equivalent lifestyle to $90k on the West Coast. There are (contrary to coastal stereotype) great places to live in the Midwest, and they are cheaper than SF, but they aren't super-cheap either. The 2500 SF houses for $300k aren't in downtown Chicago. They're in suburbs where most 25-year-olds would be pretty bored because walking or biking to work is very rare and you can't go out without a designated driver (i.e. cab service and public transportation aren't options).

If you're comparing suburbs (Silicon Valley) to suburbs, the discrepancy is much greater and I'd say that $90k/CA ~= $40k/Midwest. That's because Silicon Valley has so much less in the way of urban amenity, but still charges an urban premium that you wouldn't see 20 miles out of Minneapolis. When you adjust for commute, suburban California ("the Valley") looks even worse.