cheat by selling inferior
Jade and jade is an idiom, interpretation: show people is jade, sell people is stone, meaning the same as "hang sheep's head, sell dog meat.".
It means "hanging sheep's head and selling dog meat".
cheat by selling inferior
act without due consideration and end up in failure - jí lù wú yú
have a large army of veterans and ample supplies - bīng jīng liáng zú