> and they tend to have the worst concentration of problems such as crime and drug abuse, and NYC is one of the prime examples.

Per capita drug use in NYC isn't as bad as many rural areas, where meth has become a huge problem. The fact is that more people mean smaller percentages can still mean lots of people.

Cities really aren't that expensive compared to the wealth they produce. Its just that with scale also means demand goes up, which increases prices because resources are still finite.