Demo often starts off doing small jobs for not much money and slowly getting into bigger jobs. You need a truck and trailer to move equipment or else you're paying a lot to have it hauled from 1 and 2 day jobs or even more than 1 job per day. My former neighbour was originally in sewer and water work but transitioned into demo. I remember him talking about doing small jobs like garages and single level homes for very little money (as low as a couple hundred bucks) just to break into the demo arena. You have to build a reputation if you plan to get on tender lists. There is always competition. The first really big job he got turned into a really big messy legal battle after he was kicked off the job. I was working for him and it took 6 or 7 month's to get paid! He was kind of a shyster and very cheap, except for his kids, but the business did grow into a big operation. I think mostly because his eldest son took over running the operation. I think there's a fair bit more maintenance and repairs doing large demo than a working in the dirt.