I think this is the wrong mindset.

A better one would be: "Hire good developers. You can invest in teaching them whatever technology your company uses and/or built."

Otherwise you end up with companies that hire good developers who don't know the tech stack and expect them to be 110% productive in one week with no investment from the company in training them. Then, even if the developer can keep up with demands they end up writing sub par code due to unfamiliarity with the tech stack.

That's probably a better way to phrase it.

Pretty expensive, to be honest. Facebook snatches up most of the "engineers" and blockchain companies hire a lot of the academic community.

That being said, if you have the money, Haskell developers will absolutely follow - and in some domains the project will actually be cheaper.

The executives who think good developers are "expensive" are generally happy to throw gobs of money at BPO firms to do the job half as well as in-house staff for twice as much money.

Besides which, an employee with a fully-loaded cost of $200k/yr can be sent to a one-week external class for well under $15k including salary, tuition, travel, and expenses. That's far less than the cost of acquiring and onboarding that employee; and if you don't care to train your staff, they'll jump ship for an employer that doesn't suck the stars out of the sky.

You can absolutely get some top-tier Haskell talent for $200k/year :)