Developments of the Alchemy Hall Disciples and Elders... (2)
Looking over the alchemy disciples and elders as they sold all kinds of alchemy products to the different cultivators who had come to visit the Falling Star city, Xuan Hao decided not to interfere with them, as it was ultimately beneficial for the Star Shattering Sect and the growth of the disciples and elders to have such an easy source of spirit stones.
Not to mention, the elders and disciples of the sect would have to help supply the sect with potions or pills before they had an opportunity to sell it outside of the sect. Meaning that the current supply in the Star Shattering Sect should be more than enough to fulfill the current needs of the sect.
If not, there was no way Elder Song would have allowed something like selling to outsiders to happen, as the sect would have to be prioritized before anything else.