Here are a couple quick links on the subject:

http://www.truthorfiction.com/rumors/k/kopiluwak.htm

http://en.wikipedia.org/wiki/Kopi_Luwak

From Wikipedia "Kopi luwak is the most expensive coffee in the world, selling for between US$100 and $600 per pound."

But that is civet cat poop. I'm guessing guozili poop, being far more rare, would sell for much more.