His last bid was 40% less than United Launch
Hyperloop doesn't have anywhere near that amount of free R&D or established, easy-to-increment-to-get-there technologies to draw on.
I think almost the sae can be said for Hyperloop. There's no fundamentally new technology that needs to be engineered for it to work. Maglevs are common in many countries, evacuated tubs aren't complicated.
All that said, the US seems to be the wrong place to start Hyperloop. Regulation and land property will most likely be the biggest hurdle, not technology, especially in California. Hyperloop seems to me like a perfect project in China though, in regard to property rights, regulation, city planning, human capital in the high speed train sector, as well as crazy supply side economics.
Thus the argument needs to be that Hyperloop is intrinsically cheaper, whether built by Musk's company or any random civil engineering company. I don't see any reason why that is the case, Hyperloop looks a lot more complicated than HSR to me.
SpaceX has and continues to do amazing things, that doesn't mean suddenly everything we want is feasible.
A simpler way to make the same argument:
If Musk can actually build a Hyperloop across California at his proposed cost, he's made revolutionary improvements to civil engineering that will be far more impactful than the Hyperloop itself; the same techniques should revolutionize, well, much of conventional civil engineering! Why isn't that happening?
IDK, indeed $X/10 is ambitious but he does have a decent track record with this already. SpaceX is already $X/3 or $X/4 and is on the path to $X/10 with reusable rockets, and it's also more ambitious (rocket reuse, highest payload in the world by 2x, new capsule has powered rocket landing on any surface in the solar system).
In my mind he's earned some benefit of the doubt. Of course, there's still a ton to prove, and the idea sounds looney. You'd also have said that about SpaceX 10 years ago, though.
