I don't make anywhere near that, but yes of course, it's much better to be asked specifically for niche expertise than having to compete with everybody who can

I don't make anywhere near that, but yes of course, it's much better to be asked specifically for niche expertise than having to compete with everybody who can use Chrome to look up job sites over generic 'programmer' jobs. There are several strategies to get high-paying jobs, and 'networking hard to get an in that is not public' is an underappreciated one. But just because that process is by its nature not public, doesn't make it not common.