DD (15) has been asked to make some cupcakes for a birthday party. She is a very competent baker but not a professional, but this is the first time she's been asked formally to make some and been offered money. She has designed and ordered bespoke cupcake toppers, and co-ordinated cake cases. They will look and taste fantastic. Each cake will cost her 67p to make. She needs to provide 40 cakes.
What should she charge?