LA Times: California HSR is now more expensive: Bullet train cost estimates to rise: “Bullet train cost estimates rise to $98.5 billion. In a key change, the state has decided to stretch the construction schedule by 13 years, completing the Southern California-to-Bay Area high speed rail in 2033 rather than 2020.”

And now my estimate from 2009 (based on Reason Foundation work and the logic of the situation) of at least $80 billion, perhaps controversial, looks small.
However cost estimates have grown from $13 billion, cited in this early (1994) CalSpeed report “Revenue and Ridership Potential for a High-Speed Rail Service in the
San Francisco/Sacramento-Los Corridor” by Daniel Leavitt, Erin Vaca, and Peter Hall.