There's a formula. It takes a bit of time but once you do it a few times for each cake you will figure out pricing easily.
- How much did the ingredients and packaging cost. (Add a bit of a mark-up here because it took you time to order these things on your computer)
-How long did it take you from start to finish including clean-up, and what do you wish to pay yourself hourly? ( In MA, $20/hour is reasonable, but this is a state with a very high cost of living. It would a bit less than that in Iowa where my husband is from).
-What is the cost of your overhead, such as cost of kitchen certification, insurance, electricity, internet access, dishwasher, gas to get to grocery store, mileage on your car, childcare (if you have kids), marketing (if you market with biz cards and such) and anything else that went into the cake?
Add these costs up and you will have your answer. We don't know your costs so it's up to you to do the math. Like I said before, do it a few times and you will easily price your cakes. And don't' do it by comparing yourself to other bakeries, because they have different costs than you.