It would probably be less efficient to have a more complicated waffle machine with a dispenser attached that costs more. Having a re-usable glass or metal cup, would require cleaning, and waffle batter is kind of annoying clean. Instead you buy a big ole sleeve of paper cups that are used one time and cost $.01 each. It is more efficient than paying someone making $20/hr to spend 5 minutes a day scrubbing it.

The obvious solution is to reuse the same plastic cup for all customers each morning. Voila, now you save 309 plastic cups/day.