From “Ask Kit!”:
Q: What is a typical or average meal cost?
A: Let’s start with breakfast; anticipate about $5 per person, depending on what you are serving. Breakfast can be a very economical meal to serve.
If you plan to offer other meals, you really need to price them based on what you are serving. A spaghetti dinner will be much cheaper to prepare and serve than a steak dinner, so plan your menus and calculate all the costs involved with offering any specific meal.
It behooves you to know what the costs are for all the food you offer — breakfast, snacks, beverages — and roll all those costs into your food pricing. You are offering a total bed and breakfast package, but there will be times you want or need to break out the food charge from the lodging charge (for calculating taxes, for per diem guests, for long-term stays, for extra breakfast guests), so you might as well know that cost up front.