After reading EvArt's post on the 'Frustrated' thread I wanted to help her out and maybe this will help other people too.
So I bake completely from scratch, the reason I tell you this is: my cake batter weighs more then a cake mix and it doesn't rise quite as high when baked (depending upon the recipe). So that means people who bake using mixes will get MORE Yield then scratch bakers.
I know it's hard for our society because we are raised using cups verses weights, but the only true way to bake and compare apples to apples is to use weight only. So for this thread to be helpful, you must determine the weight of your batch, then divide it by the number of weighed scoops of cupcake batter/yield per recipe.
So here's how to cost your cupcakes and by looking at it you should be able to take theses numbers and compare them to what your slice of cake weighs. So then you can compare your pricing between a cake and a cupcake....and help you determine what you should be charging for either.
(I'm going to post this, then add more content so I don't loose anything pulling out files)