>There is another degree of freedom here: project cost. Why on earth does 0.32 miles of residential road cost $1.5M?

Well, the mayor's family member/Buddy who owns the roadworks business who needs their cut, then his family member/Buddy who owns the flagging company needs their cut and Buddy who owns the asphalt production company and so on. Then, work needs to be done as cheaply as possible, with as many corners cut as possible to ensure maximum profit possible for everyone getting their cut. Then the developers will swim around on their mountain of cocaine and money until it runs out and so the cycle goes.

This is how every developer i've ever subcontracted for has operated.