This will be long, but it is a long and complex issue:
First, you need to figure all maintenance on the tractor. Service intervals, etc. And my numbers are assuming no major breakdowns for 6000hrs.
My engine oil and filter get changed ever 100hrs, and cost $50. So thats 0.50/hr
Hydraulics get done every 200hrs, and cost $100, so thats 0.50/hr
Air filter and fuel filters, misc grease, gear oil for bushhog, ...another 0.50/hr
Tires. Figure fronts are good for 600hrs and cost $400 to replace...0.67/hr
Rears are good for 1200 and are $600 to replace...........................0.50/hr
Bushhog maintenace, blades, bolts, etc. Maybe $100 worth every 200hrs....0.50/hr
Fuel. Mine sips 1gal/hr. So $4/gal....................................................$4/hr.
Now the tractor. Figuring at 6000hrs, my $20000 equip will likely be bout worthless. At least have to assume that in the business world, because at 6000hrs, cost of repairs may exceed the value, and would be looking for full replacement anyway. So....just owning the tractor and using it....3.33/hr
Add them all up, and we are at $10.50/hr just for running the equipment. So its clear the guys that are charging $25/hr or whatever beer money, arent making squat.
Then you have to figure truck expense. The IRS # is pretty close, but a little low IMO for a diesel, and a trailer. To include towing and the trailer, you are closer to $1 per mile for expense. plus your time. So if you average 45mph towing to and from the job, and pay yourself $20/hr to drive, you would need $65/hr just to drive there and back.
Your cost per hour for business insurance is going to vary. The insurance is a fixed cost. But the more hours you work, the lower that number becomes. If your insurance is $1000/year it aint gonna matter weather you work 100hours or 1000hrs, your insurance is still going to be $1000. but cost per hour goes from $10/hr to $1 per hour.
I'll continue in another post...