To concoct the pills, one requires medicinal materials.
And not just any materials, but a vast amount of rare ones.
These materials cannot possibly be gathered over time; they can only be purchased with Spirit Stones.
When Ling Xiao left the Heavenly Dragon Continent, he left a large number of Spirit Stones for Wu Xiang, Ling Luo, and the Moon Lady, among others.
Now, while he still possessed a considerable quantity of Spirit Stones, he couldn't consider himself wealthy compared with before.
The materials for crafting the Heavenly Spirit Pills were incredibly expensive and the Low-grade Spirit Stones he carried were estimated to be enough to concoct a hundred Low-grade Heavenly Spirit Pills before being spent.
He was reluctant to use the Middle-grade Spirit Stones and even less willing to use the Upper-grade Spirit Stones.
