There are a lot of variables and some set costs,,. For set cost, take the cost of the machine plus yearly insurance,, if financed, for instance, a new 161 at 70K plus 500 a year insurance until paid off,, A 6 year note, means 73K financed divided by 6000 hrs, = 12.50 per hour... Here's the cost of the machine sitting and not working.. Add to it 9.00 per hour fuel, same for oil and grease.. Liability insurance, yearly cost divided by 400 hrs avg yearly use.. Cost of trailer , it's insurance, tags, etc,,, To pay the operator 10 per hour, one must charge 37 per hour to meet SS/fed tax, state tax, unemployment and work comp insurance. If done, accurately, a new 161 will cost in the high 80's per hour just to own... So, 120- 130 per hour is what I would charge.