Jiang He might have transmigrated to a world of Qi and martial arts, but the System that he got only provided him with... seeds. 
"Hold on, System. Aren't these just... peas? Not only are they inedible, but I'm supposed to throw them far, far away?" 

Everybody is Kung Fu Fighting, While I Started a Farm

Jin Sidao shook his head, gesturing that he had no idea.

Come to think of it, back when he heard about Jiang He's deal for spirit stones, his reaction had been the same as the Golden Immortal's.

Only someone kicked in the head by a donkey would do that.

What was up with trading 15,000 spirit stones for 10,000 spirit stones?

After musing to himself for several seconds, Jin Sidao said, "Mister Jiang might have his reasons…"

Nearby, a True Immortal sniggered out of the blue and said, "Trading 15,000 spirit stones for 10,000 spirit stones… What other reason could it be other than idiocy?"

"What, is he going to plant each immortal crystal and get two immortal crystals from a tree?"

The immortals all laughed derisively at that.

The Golden Immortal laughed as well, but said, "That said, we could work this out."

Being old and experienced, how could he not understand what Jin Sidao was thinking?

Less Than A Dog