If you want to get Spirit Stones, there are two quickest methods.
One is by killing and plundering. After all, "A horse doesn't get fat without grazing at night, and a man doesn't get rich without windfalls!"
However, this is the conduct of Calamity Cultivators, and one must be careful not to get themselves killed in the process.
Tian Lan Immortal City is not like The Great River District or Liuguang District.
Anybody there could suddenly become a great expert.
If that happened, the plan to kill and plunder would backfire, causing oneself to lose everything instead.
So Luo Chen would not choose this method.
The second method is much better and more peaceful.
Pill refinement!
Why does Luo Chen exhaust so much effort and even invest a hundred thousand Spirit Stones to secure Danxia Peak?
Isn't it to establish Luo Tian Creed?
With this power, he could mass-produce pills through refinement.
Otherwise, relying on solely on himself?