Worth its weight in gold.

"How much for that dung ball there?" the dung beetle asked the purveyor.
The purveyor rolled the dung ball in question onto his scales.
"Ten pounds."
"Ten!  For that quality?"
"This is some of the freshest dung around.  Collected it myself!"
"It's crap."
"Finest quality crap."
"I'll give you five."
"Five?" The purveyor looked almost offended.  "This is hand rolled you know.  Look I'll do you a deal... nine."
"It's not even that smooth," the dung beetle insisted.  "Six."
The purveyor stroked his antenna thoughtfully, as if he were wrestling with some terrible decision.
"Well... how about eight, and I throw in this lovely decaying mushroom too."
The dung beetle pretended to think it over for a moment.
"...Ok.  You've got yourself a deal."
"Excellent."  They shook on it.  "How would you like to pay?"  the purveyor rolled the dung off the scales and began to wrap it for the dung beetle.
"Plastic ok?"
"Certainly, this is the modern world after all.  Have to roll with the times."  He produced a pay terminal, and the dung beetle swiped his card over it.

 "Yeah, look it does this swipe payment thing now."  The terminal beeped to show that it had received payment.
"Oooh that's very clever, you're the first customer I've had with one of those new sensor cards."
"Isn't it?" the dung beetle put his card away safely and started to roll the dung to the door.  "Well, thanks for the dung."
"Thank you, come back soon!"