$12 billion for 351 km is $34 million per km.

France is planning a new 410 km high speed rail line between Paris and Lyon for €12 billion [1]. That's $11.2 billion at current exchange rates, giving $25 million per km. That seems to be a pretty normal price for high speed rail in Europe [2] for routes that don't need tunneling.

So this US project is about 36% more expensive than a typical EU high speed rail project. Higher, but is it really enough higher to qualify for "what's wrong in the US"?

[1] https://en.wikipedia.org/wiki/High-speed_rail_in_France#Unde...

[2] https://op.europa.eu/webpub/eca/special-reports/high-speed-r...