The Concorde cost ~£1 billion to develop in the 1960s. That's something like £17 billion, inflation adjusted. Also, not for nothing: "An advertisement coverin

The Concorde cost ~£1 billion to develop in the 1960s. That's something like £17 billion, inflation adjusted. Also, not for nothing: "An advertisement covering two full pages, promoting Concorde, ran in the 29 May 1967 issue of Aviation Week & Space Technology. The advertisement predicted a market for 350 aircraft by 1980 and boasted of Concorde's head start over the United States' SST project. The consortium secured orders (i.e., non-binding options) for over 100 of the long-range version from the major airlines of the day: Pan Am, BOAC, and Air France were the launch customers, with six Concordes each. Other airlines in the order book included Panair do Brasil, Continental Airlines, Japan Airlines, Lufthansa, American Airlines, United Airlines, Air India, Air Canada, Braniff, Singapore Airlines, Iran Air, Olympic Airways, Qantas, CAAC, Middle East Airlines, and TWA. At the time of the first flight the options list contained 74 options from 16 airlines." [1] Guess how many they sold? 14. LOIs for unbuilt, undesigned airplanes are meaningless. [1] https://en.wikipedia.org/wiki/Concorde https://en.wikipedia.org/wiki/Concorde