The owner clearly has no idea about the value of this possession, because it's filled with milk and the cat's drinking out of it. The man sees an opportunity for the deal of a lifetime. He cleverly strategizes a method to obtain the vase for a fraction of its worth.
"That's an extraordinary cat you have," he says to the owner. "How much would you sell her for?"
"Oh, the cat's not really for sale," said the owner. "She keeps the store free of mice."
"I really must have her," the man countered. "Tell you what--I'll give you a hundred dollars for her."
"She's not really worth it," laughed the owner, "but if you want her that badly, she's yours."
"I need something to feed her from as well," continued the man. "Let me throw in another ten dollars for that saucer she's drinking out of."
"Oh, I could never do that. That saucer is actually an ancient Chinese vase from the Ming dynasty. It is my prized possession, whose worth is beyond calculation. Funny thing, though; since we've had it, I've sold seventeen cats."