I commonly work 100 hour weeks during summer heat waves, my business is centered around HVAC repair on vehicles, trucks and off road equipment. Fell into the specialty by accident. It is hard work and long days. On good days, I make $100/hour easily so if I work that 100 hours I do pretty good for the week. Started about 26 years ago and saved my money. Don't live fancy, paid off any debt as fast as I could. Paid off what I borrowed for my first house in one year by working 120 hour work weeks back then. Never purchased a new vehicle and with the junk they put out now, I'm not interested in ever purchasing a new vehicle. Always did any remodeling and only hired the shell put up for my shop, did all the inside work myself with help from wife and 2 kids. Spent every weekend and many late nights building the shop, then I spent a few more years remodeling the house before we moved here. Always did all the remodeling on my rentals.
Once you have no debt, the money accumulates and you look for places to put it. Investments here or there. One example is I purchased a mini storage business over 15 years ago, expanded it and I am expanding again this year. I probably would have never installed solar if the Fed had not manipulated interest rates too low and energy costs remained low. But one can see the writing on the wall where things are headed and it doesn't look pretty. It might be the wrong vision, but having hedged against rising energy costs can lead to a comfortable life later and not have to do without in the future. The recent proposed rate increase by my utility of 20% is an added bonus for return on that hedge. I just don't see energy getting any cheaper and with the tax credits the government is paying to help install makes it a no brainer. Scrimp, save and invest your money. Take a second job if necessary to get the income to expand your system. Energy security and independence are the goal.