There are many variables in pricing my services
Does the client require film or digital coverage? Am I relinquishing all the rights to the images, or is a joint copyright?
How quick of a turn around does the client need? Does the client need a hard copy of the image, or will it be transmitted/delivered electronically? How many images are we producing together?  How much time will be needed at the shoot?  How much time for post processing the images?  What type of equipment will be needed?  Specialized lighting needed? Modeling/talent fees? Rental of locations needed? Is the assignment in Franklin County, Ohio?
Travel expenses? Etc, etc.
 
I generally use the National Press Photographers ‘Cost of Doing Business’ calculator to figure my costs: