Brightline is basically a conventional (slow) train, whereas the CA project goes 2-3x as fast... totally different design constraints. Amtrak in California is already as fast as the Brightline.
is that the LGV Sud Europe Atlantique between Tours and Bordeaux that opened in 2017? looks like thats €9B for 188 miles new track or €47M per mile.
https://en.wikipedia.org/wiki/LGV_Sud_Europe_Atlantique
> The consortium invested €3.8 billion, French government, local authorities and the European Union paid €3 billion and €1 billion was contributed by SNCF Réseau (subsidiary of SNCF). Another €1.2 billion was spent by SNCF Réseau on the construction of interconnecting lines, control centres, capacity enhancements at Bordeaux and remodelling the track layout at Gare Montparnasse.
A "bright line" style upgrade to the SAN-LAX route would have been entirely worth it, and they're struggling along with it, but at pennies compared to what has been spent on HSR so far.