Anyone paying someone else to mow their lawn is rich. I read that some rich people fail to pay on time. I conclude with some people, rich, poor, or in the middle, are slow or fail to pay bills. Just because one is rich doesn't mean they pay all their bills on time or have a revolving door for people to take said money. I know 'poor' people who pay everything on time and I know rich people who pay things late. Poor people can't afford the late fees, rich people can.
That's if you're in your own business. The people I mentioned were working for a company and only had to maintain their own lawn.
The hard part about the business is gas prices can change rapidly and they're working on pre-set contracts. It's hard to gauge what you should charge. I would suspect you would want to make about a 25% profit per job. This would allow for gas price changes or other events to come up. In the worst case scenario, you want to break even on a single job. If you maintain your higher profit margin, you can eat a job here and there as needed but maintain your company health.
Any luxury business.. and let's be clear, paying someone to cut your grass is a luxury, is heavily impacted when the economy goes down hill. Just as those lawn moving companies up north switch to snow removal for the winter, if the winter isn't bad, they don't make money. If the winter is bad, they make a killing. It's all about how a business is managed. There is a reason most businesses fail in their first year.
When I had my house, I paid a service to cut my grass on the same day every week. Some times they got behind and would show up a couple days late. Or other times the grass hardly grew but they came by. I always paid, but what bothered me is that they would be late and the grass would grow a little long, and then they'd cut it 2-3 days late and then come back in 2-3 days and cut it again. At one point they attempted to raise rates while doing a subpar job; I changed service on them and they got pissed at me. They wanted to charge $30/cut but I found another company that would do the same job for $19/cut. Previously I was paying $22 before the $30 number came about. I'm very business friendly, but if you're doing a poor job and in order to make that up you want to charge more, your business is in trouble and I want no part of it.
Either way, that's the risk of going into business. Should we care to bring up taxes on small businesses such as your friend's?
Or what his plan is should his business grow to the point of employing enough people he's forced into providing healthcare?
Starting, running, and succeeding with a business is likely one of the hardest things to do successfully.