Are you running programs you create? Or that the customer creates? Do you have to do work on the drawings? or do they come from your customer with everything cleaned up? How much does it cost for the operator (wages, benefits, disability, etc) How much does the floor space cost a month? What are your monthly costs for the machine?(payments, interest...) How much do any competitors charge? How much for cutters and electric? How much time is going to be spent loading and unloading the machine?
You will probably have to charge a bit less to start with, just to get them hooked, and figure out the best practices for getting the work done. After a bit of work you will get a better idea of what the real costs are. What is the going rate for shop time in your area?
Years ago I ran an old Tape Turn Regal. The shop charged twice the rate for the rest of the machines in the shop. After my first month they made money hand over fist because, once I figured out how to run it, I could get so much more work done that the manual machines. The hourly rate may sound a bit high, but if you are runnng it right you should be getting things done faster so the end product doesn't cost any more.