Among them, he listed even over a hundred, Su Xing obtained various special metals and other resources through trade from the Three Thousand Worlds.
But not all of these resources possessed high energy value.
Su Xing selected four types that had an exceptionally high cost-performance ratio, containing a vast amount of Origin Energy Source.
Among them, the iron essence was just a more common mineral in the Cultivation World, with a sturdy material, but the energy value it contained exceeded Su Xing's expectations!
One iron essence, in the Cultivation World, could be purchased for about 10 low-grade Spirit Stones.
Ten thousand low-grade Spirit Stones could buy one thousand iron essences!
While one low-grade Spirit Stone, the price Su Xing brought out was 1000 energy points; ten thousand low-grade Spirit Stones, then, equated to ten million energy points! (Note, this is energy)
Ten million energy points, worth 10 points of Origin Energy Source, did not sound like a small amount.
