How much should I be paying for labor?

I have been doing home improvement for 35 years, because of health reasons I have to stop doing manual labor and hire people. I can still do small roof repairs, but for replacement I am going to need some help. Many years ago I used some subcontractors, but I was never happy with their work. I was thinking of using day laborers and supervise them. The Big question I have is how much should I be paying day labors, and how much should I be paying subcontractors?