I never made it more than 3 years each working for the 4 repair companies I've been at. Two were dealers selling new equipment and one was a independant. Then I went out on my own. It really didn't cost much at all to get going. That was 25 years ago.
I did have 2 big customers all set to go when I started. Things have been good and I would not have done it differently. I'm totally free, I do things my way.
Along the way I joined another independant but that only lasted 6 months and I went back the way I was, all by myself. I had another company want to buy me out and come work for them. I commented, "But then I wouldn't be the boss and I would have to work 8:00 to 5:00", no thanks!"
Three times, over the years, my biggest customer has gone out of business but I always picked up another afterwards.
It is very easy to blow the dealers out off the water with my rates, quality of service, and honesty. My customers know this and seem to like me a lot.
I almost like my job, except for the dirt and grease.