This doesn't seem terribly surprising. Even a hole-in-the-wall restaurant probably has better economies of scale ingredients-wise than even a large household.

This doesn't seem terribly surprising. Even a hole-in-the-wall restaurant probably has better economies of scale ingredients-wise than even a large household. On the other hand, restaurants charge for their labor - and if a restaurant meal is cheaper than cooking at home, then it's yet another suggestion to me that restaurant workers are underpaid.