It isn't about size, it's about the nature of the foodstuff. A biscuit is basic. A chocolate biscuit is luxury. Cake is basic Meals you cook at home are bas

It isn't about size, it's about the nature of the foodstuff. A biscuit is basic. A chocolate biscuit is luxury. Cake is basic Meals you cook at home are basic Meals someone cooks for you (e.g. restaurant or takeaway) is luxury. (among other examples)