As a hiring manager, I can confidently say that we are nowhere close to saturated with talented software engineers.

so the niche is in training ? :D

Yes, I earn 3x more doing training than myself or any of my senior SWE colleagues/friends. Think 1500 EUR daily rate instead of 500 (in Central Europe).

* talented very experienced software engineers under 35, who are willing to work on-site full-time (which often means move to the company) and are allowed to work in the US?

Or am I being too synical?

Software is the easiest thing in the world to outsource. There's no reason we can't play Chinese-made games or use Indian-made chat apps

Market forces (more demand than supply) are what push coding salaries into the stratosphere

Okay. Sounds like your demand exceeds your supply. This bodes well for your candidates, whose skills are in demand. But you are also not paying infinity dollars for them, right? I was just stating that, all else being equal, if there are more suitable candidates per given position, you could end up paying less, because of the higher competition. Once you get into highly specialized domains, both competition and mobility decrease. Ideally, one might seek specialist-level salary for otherwise-generalizable work.