Now supposing your CoL is halved, your CoL needs to have been $150k+ for this to be worth it. Since you lose $75k in pay, and need to make that up from the CoL difference. If you're single, chances are you weren't spending that much on food and housing, so you actually end up with less money. But if you're supporting a big family, you may well have been spending most of your money on necessities and the CoL reduction is worth it. (At least financially.)