In a 1 gallon container mix 2 cups non dairy creamer ($1for 3 cups) at the dollar store, 1 cup nonfat dry milk, 2 tbs sugar or honey, 1 tsp vanilla. add water slowly while stirring until gallon container is full. Serve as milk.
Use nonfat dry milk for cooking.
Cost is about 1.50/gallon
After kids try it, you will have trouble going back to the store bought milk. This just tastes better.