How do you all charge for 1/4 sheet and/or a 1/2 sheet dummie cake? simple just roses.

Thanks for you time in answering my questions.

I've never had a request for it, but if all they wanted was a dummy cake, it would be the same price as a regular cake. The styro's can cost more than my cake ingredients (I priced them out); same icing, same time to decorate, same talent to create it....same price.