This here's a perfect example of "Time vs. Reward". The older I get, the less I want to f with things. Yes, absolutely I could of re-shingled my 40'x80' shop myself this spring with a little help. It took the outfit 2.5 days. And that's from the time they pulled in the yard to the time they left. They had it tore off and shingled in less than 2 days. Yes, I had to fork over some cash for it. But I didn't have to waste 3 days of my own and then 3 days to each guy that would of helped me!!
My view is if you don't feel comfortable doing it yourself, pay someone to do it the right way. Don't know how many times I've been involved with the "hell we can do that, and I guarantee it will be better than they would do it" theory..... Then it turns out looking like a blind-man's work and you end up having to re-do again it anyways.
Time is to valuable to me.