Not sure if this is the right forum, but here goes...
How much per serving do you charge for a 3D cake? I am doing a truck that is about 20"x7"x7". They needed 15-20 servings but said I could go bigger if I needed to for the design.
I charge for the number of servings in the original cake I had to make to carve. So if I had to make a cake that serves 24 to get a 3D figure that serves 15, I charge for 24 servings. I've heard of several people who do this. Of course, I try to make the original cake as close to the number of servings the customer needs as I can, but it's in the nature of carved cakes that some is lost in the carving process.