[cartoonp]

An art collector is walking through the city when he notices a mangy cat lapping milk from a saucer in the doorway of a pet store.
He recognizes that the saucer is extremely old and very valuable, so he walks casually into the store and offers to buy the cat for £10
The store owner replies “I’m sorry, but the cat isn’t for sale.”
The collector says, “Please, I need a hungry cat around the house to catch mice. I’ll pay you £50 for that cat.” And the pet shop owner says “Sold!”
The collector says “Hey, for another £10 could you throw in that old saucer. The cat’s used it and it’ll save me from having to get a new one"
And the owner says, “Sorry pal but that’s my lucky saucer. So far this week I’ve sold 68 cats!”