CAD solid modeling prices?

I was hired to make a 3D model using AutoCAD (there will be no rendering, I will be given the object and its measurements). It is a fairly simple project which I expect to take me 6-7 hours to complete (including any reworking they want me to do). Since I've never created a drawing for a company before, I have no idea how much I should charge for my services. I figure I should come up with a per hour figure for my own time calculations and then just tell them the total sum. Does anybody experienced have an idea?