No reason other than the fact that Wang Fugui's wealth continues to expand endlessly; Yan Gold, Immortal Crystal, Divine Spiritual Treasures, copious amounts of Purple Abode Treasures, and even Fine Magical Treasures are being continually scavenged, along with all sorts of precious refining materials, Spiritual Medicine, and even finished Dan medicines.
There's even a vault with several top-grade Spirit Stones stored inside.
These top-grade Spirit Stones are extremely precious; those like Jade Spirit True Monarch, who aspire to reach the mid-late stage of the Transcendent Void Realm, are exceedingly eager for these Spirit Stones. Their price is approximately equal to a hundred million Qian Gold.