It depends on where you live. In Utah, we have sooooo many longarmers, and they all have all the customers they can handle. We have one lady who only does pantographs, and she has a great business. So many have the computerized robotics -- I think that's the best way to do business with a longarm.
I have a longarm, but really don't like quilting for others. I'm just not very good with free-motion and don't have the robotics. I do better with rulers, but they take more time.
The going rate for an all-over edge to edge design is .015 per square inch. We have a couple quilters who charge by the hour at $25 per hour.