A donations system will only go so far. I thin and SMT would be a workable solution to both rewarding teachers and keeping tutorials affordable for students.
What we want to achieve could be seen as a sort of donation system, but from peer to peer like Twitch. I hope that students/learners want to voluntarily pay for the tutorials that are actually useful to them, and not have to purchase tutorials first and then find out, it was a waste of money.
That's not a bad idea i guess from a student's perspective. I haven't used Twitch so I dont know how it works on a practical level.