Yes, I meant median salary of all people living in the area. Not of developers.
For example, here in Boston median salary is $58,000. Developers can readily get $116,000, and I know many who have exceeded $174,000, at least when taking into account bonuses, RSUs, etc.
My point is that plenty of people obviously afford to live near you while making only median salary. If you live the same lifestyle as them, you have a huge ability to save money.