Xiao Yang had already finished half of the flowers in the garden which alone was a large number. There were easily over a hundred flowers in the garden which would be a terrifying number if they were brought to be sold. The Ten Apertures Blood Vein flowers were something that could actually be sold for tens of Immortal Stones.
Immortal Stones were similar to spirit stones, but contained Immortal qi instead of spirit qi. One could say they were an upgraded version of spirit stones and were only found in Immortal worlds and above. They were a lot more valuable than spirit stones.
Even if someone had a million high grade spirit stones, they might not be able to exchange it for a single low grade immortal stone. It wasn't even a matter of cost, but rather the change it could bring forth.
