Earlier quoted context omitted.
This adjustment is on the extreme end to be sure. If you make 80K where I am and live in the square footage I do, a comparable place in SF is around 3K* more expensive per month. So there's a very real, ~36K negative adjustment to that 120K SF salary for me. *editted
You must have an insanely huge apartment for rent to increase by $4k/m by moving to SF. But even assuming that -36k adjustment, you're much better off making $150k in SF than $80k in Kansas City. Of course, you also have the option of downsizing into a smaller apartment. The amenities in a large city make it much easier to have a small apartment (for example, in NYC I drop off my laundry instead of washing it at home…
I bought my house when I was making about 60k. My last local job paid 220K, working for a company that is now being bought by Bayer, so I have seen the difference between 80k and 150k. 80k in a cheaper place is far better, especially if you are renting.
As far as dropping off your laundry, then you also have to consider that you are spending more money per load of laundry than I do by using the washing machine.
Now, what is true is that cost of living calculations are not linear: A simple multiplication doesn't really capture the differences between making 30k, 60k, 80k and 150k in the same location: There is a point after which cost of living doesn't matter: In St Louis, for instance, I'd argue that anything more than 70K or so is just flat, past tax rate differentials, because you are talking luxuries that are about the same everywhere. That line, however, is way past 150k in San Francisco, because housing cots are nuts.