As you will hear from everyone pricing is based on your cost and your area not someone elses. So you need to figure out how much it's costing you per cupcake. You then need to research your market. How much do other bakeries charge (not walmart or target) but actual bakeries. Are you cupcakes special? Gluten free, gourmet flavors...high end ingredients.
All of this comes into play in your pricing.
My cupcakes are $2.50 each and that is filled and frosted with a big swirl (or dipped in ganache) and this is my gourmet flavor line. I don't price out "vanilla cupcakes with buttercream". It's not what I want my business to be. I will do them upon request especially for kids parties but why would someone pay custom prices for basic cakes. That price includes sprinkles or a small fondant flower. Anything more elaborate and prices go up. I don't do minis or jumbo.