If we're talking about teachers as a consumer group perhaps we could at least think for a moment where that group is going...
I will admit that I don't know for certain that total disposable income of all US teacher finally reach zero in N years. But if a person is thinking of getting a teacher to buy their product out of the teacher's own pocket as a sales strategy, that person should keep in mind the number of US politicians who essentially say all public servants should be fired or live on starvation wages.