“By the way, it is completely halachically assur for rabbeim to charge money for the teaching of Torah. ”
1: The obligation to educate a child, is on the parent, not the rebbe or yeshiva. A parent who chooses to use the school as a shaliach, is obligated to compensate that shliach for their time.
2: Why assume the Rebbe is “charging” anything. When was the last time a Rebbe or Morah sent you a bill?
3: Supply and Demand? So, where is the readily available supply of teachers willing to put in 25 hour weeks for 35k a year? If it existed, the schools would hire them in droves, (assuming the parent body would go along with it – the demand side of the equation).