Just imagine what they make when they’re on overtime!
Actually that probably figures in the shift time and overtime typical of the job.
I had a neighbor who did this sort of job in the midwest and while he didn’t make this much, he was very well paid. It is a niche job because some productions don’t have the union mandate but some do.
The big touring productions that came to town had to have someone when they needed the heavy and/or high rigging set and the expensive touring company equipment put in place with special electrical needs etcetera.
Its kind of like being the guy that sets special security equipment for nuclear bases -— not a lot of demand, but very specialized when it is needed.