C784 Stone Gambling
Perhaps, in order to earn money, Tianji Sect had mixed ordinary rocks with high grade ores and tricked everyone of their money. It was not impossible. Moreover, these ores were not cheap. There were tens of thousands to hundreds of thousands of pieces of ores. The most expensive ones cost millions, or even tens of millions.
F * ck, this is a gamble. It's like buying a welfare lottery ticket