I haven’t had time to watch the documentary yet, but my first thought about a $5 price tag is that it can’t possibly be accounting for inflation.
$5 in 1977 is about $21.15 give or take a few cents according to most of the website i checked the numbers on.
So while it might be $5, that was definitely not as cheap as it might otherwise seem.
Regardless of the inflation adjustments, ~$20 is surprisingly inexpensive for a commuter helicopter ride, I wonder if the economies of scale really do bring it down or if they were still eating their losses trying to grow business at that price.
The flat rate has only been in effect for several years. I would assume it would be a lot more expensive to take a taxi from midtown directly to JFK before the flat rate.