I did use the word revenue in scare quotes for a reason - I don't expect that all that money could be given directly to the teacher. On the other hand, the stat

I did use the word revenue in scare quotes for a reason - I don't expect that all that money could be given directly to the teacher. On the other hand, the state should be able to achieve quite high economies of scale on administration and purchasing (whether they actually do is something else), and there's no profit to make at the end of the day. I was actually thinking 50% would make the math easy but probably be a bit unrealistic, but I arrive at about the same place as you I think. Also I'd imagine that most classes are larger than 20, but hopefully smaller than 30.