I work for the family business (dad & uncle started it thirty years ago).
They still do ten hour days 6 days a week. They work hard but love it. We have 30 employees and have had up to 100. 30 is alot more manageable, but our overheads are still pretty much the same, which brings in profit margin. To pay that amount of people each week is tough, especially when clients don't pay on time or have 45 days to pay. That's 7 weeks of pay before we get money in!
Alot of people think to make heaps of money you need to have your own business. But then it's your assets ie house, car, investments etc that are on the line when things go south. It can be totally out of your control, especially if a builder/client goes broke half way thru a job... (Happened to us twice & cost us LOTS)
Do your research and be prepared to put in lots of time and money to get it moving. The rewards are great but the time spent is heavy. My dad and uncle could work for someone else and probably earn twice as much without the pressure of losing assets, finding work for 30 odd people and finding/chasing $$$ like they do now.