Note that the 787 development costs included building multiple full-sized prototypes of a wide-body (read: price on the order of $225M per aircraft) and a movin

Note that the 787 development costs included building multiple full-sized prototypes of a wide-body (read: price on the order of $225M per aircraft) and a moving vehicle production line — you can tour the Boeing plant at Everett and see fourteen Dreamliners lined up nose-to-tail at various stages of production, like 200 ton automobiles in a car plant. They also built a global supply chain, with over 50% of the components manufactured outside the USA (for WTO trade rules compliance — a side-effect of Boeing's ongoing trade war with Airbus; Airbus have had to do the same). With over 1200 orders to date (over 500 delivered) the 787 has only been available for 13 years: typical product life of a Boeing/Airbus airliner is 30 years, so they're looking at amortizing that $30Bn over roughly 2500-3000 airframes, and you should consider it as covering most of the manufacturing costs. So the $30Bn sticker for the Dreamliner gets you not only a new wide-body airliner, but a whole new global airliner manufacturing supply chain (you bet they'll use it — or a development thereof — for the next airliner they design, too), and the capacity to punch them out like pick-up trucks. This $33M funding round is to build a one-third scale flight demonstrator. Not an actual Boom airliner, or a Concorde equivalent, but something like like the HP.115 — a research aircraft with similar flight properties in some parts of the flight regime of the planned final aircraft, for test purposes: https://en.wikipedia.org/wiki/Handley_Page_HP.115 https://en.wikipedia.org/wiki/Handley_Page_HP.115 (Significant difference: the HP.115 was used to investigate low speed stability and handling of delta wings. The Boom XB-1 is to investigate supersonic low noise flight.) It also lets them build up their engineering team to the point where they're actually able to get a full grasp of the magnitude of the problems they're facing. But a real Boom supersonic transport? That's going to cost at a minimum multiple single-digit billions (even if they don't go all-out and budget for a production line and supply chain for 2000 units) to develop.