1) I'll cite the San Jose viaduct as a shining example of "out of control" spending. There was some
lovely analysis that I
cited back in the fall on this point.
2) The most comparable line I would offer is the Tōkaidō Shinkansen line from the 1950s, which ran about $1bn (the cost was around 380 billion yen per
this link and as confirmed elsewhere; please remember that this was under a far different exchange rate regime). I'm not
entirely sure what this would translate into in current dollars (again, funky exchange rates stink), and I think the land in question
was flatter (in spite of it being Japan), but I doubt the multiplier would be 50x+.
Now, I can't speak to the pre-existing infrastructure, but IIRC they're using basically the same lines they set up in the initial project now, and this line was even more revolutionary then than CAHSR is now.
I could also point out that the first TGV line ran, in real present day terms, around $4-5 billion (accounting for inflation and exchange rate differences, I believe). Mind you, that line is shorter...but again, even scaling the project up a few times still gives wiggle room to come in cheaper.
3) And actually, taking the Tōkaidō Shinkansen again for a moment, the chairman of the project pulled this same lowball pricing trick...and resigned when the real cost became clear.
4) Finally, on the damned if they do damned if they don't: Really, they doubly damned themselves. They lowballed the initial cost and then were shocked when tripling the cost (for
whatever reason) on a project this size jolted a lot of people and had to scramble a new project plan together to fix the damage that had done. If they had come out with a higher number to begin with, then it is true that the project might have died...but at least then there wouldn't be $3 billion in federal funds tied up in it right now that could be funding other projects (notwithstanding the FL meltdown, there are
plenty of places that money could be going). And if they had come out with the $60 billion-range numbers in November instead of the $90-100 billion range numbers, yes, there would have been shock...but I doubt it will have been
quite as bad.
So if it succeeds, yes, it will be because they bent the estimates as far as they could to one side and then kept the project together in spite of the surprise when those numbers snapped back into place...the success will be in spite of borderline fraud being revealed. I find it telling that the spike in estimated costs came
after funding was committed. And if it fails, then it will be because of the same games being played...only that they were being played in a hostile political environment instead of a friendly one where this stuff is gotten away with.