I haven't read this text, although it seems interesting.
This idea is one that I live out and set up communities to reproduce. I get it from Jesus' words, "Freely you have received, freely give." And we see this in practice with the original Simon (where the word "simony" comes from), who wanted to purchase the power of the Holy Spirit from Simon Peter.
Wit probably wouldn't be equated with education. Even in the time of the Plowman, the University of Paris cost money, and so you could take that education and sell it.
But ideas should be free. Not books-- paper, pressing and distribution costs money. Water should be free, but not potable water. Weather should be free, but not energy obtained from weather. Fire could be free.
But I receive a lot of food, water, etc for free. So I give it for free. I receive books for free, so I give them away. I receive donations, so I shouldn't charge people for what I receive for free. I received a house for free, so why should I charge others to live with me?
It makes sense in a religious context. In a society in which our survival and our worth is based on what we can sell, it is difficult to convince others of. But I'm anti-capitalist, so I can talk to like-minded folks in that way, or people who believe in certain kinds of community living.