the costs in NYC vary wildly. Manhattan is very expensive, Staten Island, not so much.
But most folks don't want to live in Staten Island, hence why it's cheaper. They want to live in the most expensive places, and hence they tend to live beyond their means.
I think that's true for any city though. In my own city, people complain about the very high costs in the most expensive areas, but they never complain about the costs in the cheaper areas... and if you point out those areas exist they tend to get angry with you, because it's not desirable to live in the more affordable areas.