Iceblossom just opened another possibility for you. I have a couple of friends who are very happy to let me use their machines, however, unless I am quilting a donation quilt (a very very good way to learn and get more proficient) I always insist on 'renting' their machine--and their expertise. I am never totally alone so someone is always around to offer suggestions, help right an oopsie, and make sure I am following all the steps in the correct order.
Both friends never want to take money so I have made up my own fee schedule depending on the size of the personal project that I quilt on their machine. I insist and they finally agree. That money usually ends up helping them to pay for batting or backing for more of the guild's donation quilts.
Snooze also has a very valid point. Make up an order form stating the size of the top,who is supplying batting and backing (make VERY sure that the measurements are accurate and backing is adequate) the pantograph and thread colour selections, APPROXIMATE total cost, time frame and down payment. Both parties should sign it and each should have a copy.
When deciding on price per square inch (that is the way it is charged here) check out what some of your competition is charging. You may wish to undercut them a bit until you feel more confident. However, that could be a double edged sword since customers often complain about the cost of professional quilting and might flock to your door, leaving little time for your own projects.
Good luck with whatever you decide.