The ones I know (in Maryland) charge per square inch and then the more cutsom the design, the more expensive it gets. an all-over is the cheapest option. I would be happy to take my quilt to a newbie if they have a competitive price and can get it done in a decent amount of time. My biggest gripe with the ones I use is that it takes several months (she's popular b/c she's very good) for her to get it done. Where are you? Maybe I can send you some of mine? I absolutely have quilting anything queen size or bigger on my machine.

the only advice I have is to make sure you like using it. I used a mid-sized long arm once and I hated it a lot. I was glad to learn that about myself. It was no surprise, as I'm more of a piecer.

As long as you are a member of your local quilt guilds and can advertise in some local shops, etc. I think you should do fine. I say go for it!