You must add up the cost of all the ingredients including box board ribbons etc. Be aware of parking fees, postage and packing from online sugarcraft warehouses and sundries like this. Also I would advise keep a close note of the amount of time it takes you to design, consult, bake, clear up, decorate, deliver etc. As this is where time seems to disappear. I would always hunt around in my local area to find out rough prices for similar styled cakes from bakeries, and ensure as a home baker I was charging less – but use their prices as a guide, since they have all the overheads of a shop. Some cake decorators I have spoken to simply do not charge enough for their time, nor even price in for equipment replacement. But you have to make sure your product is every bit as good as the local shop too – in order to get paid a sensible sum of money for your time.