I saw this movie all through the 70's and always liked it. I just bought the DVD and find thatm for the most part, the movie has aged very well. But one thing that I could'nt believe is that for all their trouble, the hijackers were asking for only- "One Million Dollars"! Unbelievable.
And even more funny is the mayor's response:
"One million dollars!?! - This city (New York) doesn't HAVE one million dollars!!
This is a great movie though. I highly recommend this one.
For what it's worth the Old Man hostage asks how much money the hijackers are going to get. When Mr. Blue tells him $1 million, the Old Man responds with the line "That's not so terrific".
Actually, 1 Million dollars for four people was an extremely significant amount of money. After this kind of theft, they would leave the country and end up where the cost of living is pennies on the dollar compared to costs in the US.
Rather than looking at just price index, it might be better to look at NY prices. Back in the early 1970s, the average rent for an apartment in Manhattan was $300/month. Now its around $4000: an 13 fold increase. By this standard, $1 million would be the equivalent of $10+ million today. Another standard: I just googled and the average price of a NY apartment is 1970 was $45 p/ sq ft. Now it's $1200/sq ft. Assuming a 1000 sq ft apartment, $1 million back then would buy you 22 apartments. Now not even 1. Either way you look at it, $1 mill back then would have set you very comfortably for life.
Also, for the average movie goer in 1972 $1 million would seem an outrageous amount. Remember, we didn't get billionaires until the 1990s (ignoring Rockefeller): a million was viewed as the apex of wealth.. Had they made the ransom more than that, the 1970s audiencemay have rubbished this movie as being too ridiculous and outlandish.
This type of thinking is all too common among movie viewers when watching old movies. I suggest all those unfamiliar with inflation and its effects consult the US Labor Department's inflation calculator when they are curious about the money sums mentioned in old movies. Link is http://data.bls.gov/cgi-bin/cpicalc.pl.