And it costs a lot because, originally, it was stupidly placed at a spot where the river crossing is 3 miles wide, with a mucky floor... instead of just a bit south, where the river is one mile wide with a solid rock floor.
The bridge was only built where it was because it had to be 25 miles away from the Statue of Liberty...
...otherwise, the toll money from it would go to the Port Authority instead of to NY state.
source: NPR story