One thing else to consider.
When I took an early retirement offer from At&T I had several people wanting me to build cars for them. I had the shop space and decided that I would do restoration work for a living. I was never without work and was never cheated out of a dime ....BUT......In less than a year I lost all interest in my own cars. I realized that I could have a career or I could have a hobby but could not have both. I went to work at a heavy truck dealer and went back to playing with my cars for fun.
There are a few people who can work on a customer's car all day and go home and work on there own but they are few and far between. There are also guys who would just as soon work on a customer's car as their own.
For me, My old cars and my social life are all tied together and I don't want to turn it into a living. There definitely is a demand for good technicians. Unfortunately not many of them are earning what they deserve.