I believe you when you say there is a lack of competition, but it seems like the system is set up to prevent that from being consequential: as I understand it,

I believe you when you say there is a lack of competition, but it seems like the system is set up to prevent that from being consequential: as I understand it, the price should be set as a function of the prices of competitors outside the airport, per the Port Authority's own pricing rules. So, lack of competition inside the airport would not by itself be able to explain this pricing. Corruption or incompetence within the Port Authority would explain it, and though I will withhold judgment, it's hard to think of what else it might be. It's even easier to jump to that conclusion when they also deny and conceal when asked for an explanation.