true --- NYC is more expensive than the cities mentioned, but all of the cities you mentioned require a car (yes I know Chicago has a train, but it's not super convenient, the other two cities absolutely require a car).
A car requires a car payment, an insurance payment, gas, maintenance (tires, oil, general problems). Not to mention while your sitting in traffic, you cant work or a read a book or study math, learn a new language etc. Long car-based commutes degrades your lifestyle. I think most people that have this perception NYC is outrageously expensive, but they do not take into account the expenses they endure when they live in other locations.
Groceries are not double the cost of other cities here either. If you go to whole foods, that might be true but there are a ton of options to find fresh, reasonably priced food.