>From an expenses stand point it seems intuitively obvious that the per capita cost of individuals is lower in high density areas.
A lot of things that seem obvious aren't actually true.
>And from a tax revenue standpoint city's get ~4.5x of their revenue from property taxes than from sales tax. And most suburbanites, like urbanites probably spend most of their tax near where they live.
The city has some control over the mix of revenue sources. NYC has an income tax, and San Francico gets more than twice as much money from "service charges" as it gets from property taxes.
In terms of where people spend money, suburbanites spend a lot of discretionary income in the local city, particularly in places like restaurants and bars.
Let me ask you this: If it's so much more efficient to live in a city, why is everything more expensive in cities?