It doesn't matter what you can buy in San Francisco, that doesn't justify paying me less to do the exact same job with the exact same educational requirements. Our company made that argument during our last contract negotiation and failed to convince anyone of that. Turns out you get quite a few volunteers to move to the high cost coasts if they're going to pay you more to do it. I have to agree with @Nephilymbass. I've also lived in quite a few different states and economic areas and IME the cost of living thing only works out if you're willing to drive and live in at least what I consider subpar housing. Not to mention the lack of promotion opportunities being out of the main loops in most national companies.