It's the "legit" part of your statement that answers your own question. Would any of those service people you mention consent to do their services in the nude for more money? Why not? Or pop a cock in their mouth for a few minutes? What's the big deal? Because it IS a big deal. Those service people would be laughed out of town.
In our society, us providers can tell NOBODY what we do for a living and NOTHING that goes on in the job for fear of:
Reprisals - from pissed women, calling us names, trying to shame us, maybe physically hurting us. From men, same but also trying to rape us (she must love sex, she does it for a living)
Getting kicked out of where we live and/or work because of angry neighbors.
And jail time and definitely court time, penalties, a criminal record making regular work impossible.
And getting kicked out of families, losing friends, living a pretty isolated existence.
So yeah, we charge a lot. The only professionals that charges similarly are doctors and lawyers.
And we do both, we listen closely to your woes and wails, give advice (sometimes good - I gave a client the name of an invention he created which he markets it under now) and we give you sexual healing.
Please think about that this holiday season.
(end of rant)