Four listings on this page put the whole cabin at your disposal, and the pricing works differently from a seat.
The couples flight at $937 is the cheapest private cabin here and by far the best evidenced: 295 reviews at 4.9, thirty to forty-five minutes from Westchester. For two people that is roughly $469 each — about twice a shared seat, for a guaranteed window and nobody else in the aircraft.
The charter for two to six at $1,610 is priced for the aircraft rather than the person, which changes the arithmetic completely. Split between four people it works out at about $403 each, which is less than the couples flight per head and barely more than the longest shared seat. If you are a family or two couples travelling together, this is the listing to look at rather than buying four separate seats.
Above that sit the proposal flight at $3,558 and the scenic charter with champagne at $4,415. Both are occasion products rather than sightseeing, and both are priced accordingly. They are worth the money only if the occasion is the point — and if it is, they are worth it, because the crew knowing what is about to happen is the whole difference.