Bobbielinks,
With respect, you appear to be undervaluing your expertise if you are charging the going rate for all over quilting for your custom work.
MSQC charges 2 cents per square inch for all over designs, extra for batting, backing and binding.
I am sure rates vary by location. LAQ in cities will have higher overhead. Those in the country will have to cover the costs of longer trips to the post office, or if they only accept quilts in person, fewer local customers.
I checked a couple Canadian sites and 2 cents per sq/in is standard, with one site currently having a 6 week turn around time, and looking to hire more staff, so they can work until 11 pm. These are mail order sites.