Nothing complicated. Cost of ingredients+cost of my time(reasonable)+ cost of any necessary equipment+ tax= your price. Any gratuity is optional.
I frequent food blogs daily, i subscribe to various food magazines, and at night watch cooking shows...so i'd say my time is well spent keeping relevant.
At an early age food became my calling. I took all of my mother's cookbooks and cooked through them. Working in a professional kitchen, one often times looses that personal interaction and customer appreciation for YOUR food. So i do this to get closer to my craft and the people who enjoy it!