This has already been discussed somewhat. But here are some other steps we take.
We leave course fees up to the individual teacher. They may charge much or charge nothing or something in between. Of course, "much" in this case will be felt differently by the teacher and the student. Hence, the fee set by the teacher is usually negotiable. Each student works out remuneration directly with the teacher.
Cost mitigation options are also determined by the teacher. For example, a teacher might accept a share in a CSA farm, or auto repair, or a bicycle. Another teacher provides a discount for full cash up front. Not all teachers will use a given method of fee reduction or replacement, but some will, and inventiveness is encouraged.
The point of all this is to humanize economics, to encourage transparency and dialogue between students and teachers about money. We neither love money nor fear it.
But … How to afford the fees if you still find them too high after cost mitigation.
And … here's more of our original thinking about finances, so that you can see how we arrived at our current structure.