Pricing Dilemas!

As a newbie in the Home Staging business I am grateful for the information sharing of Active Rain!  It's the best thing I have discovered since, well, I guess I was about 18 years old...  Anyway, does anyone have a formula for figuring out what the services of a Staging Professional are worth?  I belong to a small cooperative group of stagers and redesigners and we are all struggling with this!  Has anyone actually sat down with an accountant to try to work this out mathematically based on the cost of providing services? Any help would be greatly appreciated.  We are conducting business in a small market of about 80,000.