C81 Treasure Pavilion

Take Du Siming, for instance. The feather fan he wielded was a high-grade Yellow Rank weapon, sufficient for his use until he reached the Mystic Soul realm.

Beyond that, one would need a Mystic Rank weapon. Such weapons were a matter of luck to find, and even the Dubhe Academy had only one low-grade Mystic Rank weapon for sale, priced at three billion high-grade soulstones