I have an inordinate amount of information on the Boeing 2707, the plane that would have competed with the Concorde if it hadn't been killed by the Senate.
The economics would have never worked. The fuel necessary to keep that pig in the air is off-the-chain; the 747 didn't exist yet but the Boeing SST (and the Lockheed) would have gotten you there with something like 4 times the fuel. And that's according to the sales literature. It probably would have been more like 5 or 6 times, considering the engines were common with the XB-70.
The Museum of Flight (which is basically an homage to Boeing, so not exactly an unbiased source) will happily tell you that their pet Concorde would fly you from London to New York for $10,000 and only lose $7,000 at that price. 128 seats x $7k loss per seat = a government subsidy program writ large.
Theoretically, they're trying this shit again. Practically, gas hasn't gotten much cheaper and it still requires a shit-ton of power to push tons of anything that fast. There's a line in Sled Driver where Shul points out that each J-58 has the same shaft horsepower as the Queen Fucking Mary.
Your choice. Two dudes at Mach 3 or 4,000 dudes at 28 knots.
The Concorde didn't suck. It was just the ultimate expression of a mode of travel that was utterly unsustainable.