I attended a 'quilting for business' class by Sally Terry at the AQS show in Des Moines--she agreed with many of you, saying that you need to list what is a given in your long arm business (i.e. anything that is typically done for every incoming quilt); and then what type of quilting will be done (all over, custom, heavy,etc); batting and backing. And listing all inventory and cost of inventory used (i.e. batting and backing); and extra services such as attaching the binding, etc. She said that you need to know how long arm quilting is typically priced in your area--by the sq inch or by the sq foot. she then gave us lots of ideas for marketing and she obviously loved that part of the business.
Seems like quilting for a profit is like any small business--you won't really make much $$ to start with and you'll have some expenses getting it off the ground. I've already spent $$ for classes, the long arm machine (LOTS!); thread, templates, business cards and samples--both of my quilting and quilts that I can use to hang in LQS so they can refer to me. I can do this cause I've got a pension to pay the bills--would think the the OP could probably supplement her income with quilting for others, but probably not in a position to dump her job and support a family on quilting if she's like most of us. But who knows--she may become the next major designer!