Amtrak charges the market clearing price. There is quite frankly a fuckton of demand in the Northeast corridor with its 52 million residents along the one line,

Amtrak charges the market clearing price. There is quite frankly a fuckton of demand in the Northeast corridor with its 52 million residents along the one line, and not a whole lot of rail capacity due to the fact that Amtrak barely has money to keep the lights on and the NEC is 100+ years old and in need of significant capacity upgrades. (There are only two tracks connecting New York to the entire south and west of the country, for example.) Even at the very high Amtrak prices the trains run full.