The elder that spoke didn't care that few people were willing to sell what they got to thr sect. He only cared that they had made the oath and that no one would do anything stupid like selling the things they got from the secret realm to others.
Selling those precious plants to outsiders is a bad idea because there is no place to buy them outside of thr sect. The only place to acquire them is within the sect, so it makes sense to maintain the circulation within the sect.
What's worse than selling to outsiders is giving those things away for free to outsiders. As ridiculous as it sounds, it has happened before.
Some people gave their things to family members outside of the sect. This might sound reasonable, but the elder doesn't think so.
The elder thinks it is an insult to give away things that many people died for. He thinks it is an insult to those people who risked their lives and died in the secret realm.
