Two dollars

Jim walked into a store which had a sign outside: "Second-hand clothes bought and sold." He was carrying an old pair of pants（裤子，短裤） and asked the owner of the store, "How much will you give me for these?" The man looked at them and then said rudely, "Two dollars."

"What!" said Jim. "I had guessed they were worth at least five."

"No," said the man, "they aren't worth a penny more than two dollars."

"Are you sure?" said Jim.

"Very sure," said the man.

"Well," said Jim, taking two dollars out of his pocket, "here's your money. These pants were hanging outside your store with a piece tag that said $6.50, but I thought that was too much money, so I wanted to make sure how much they were really worth."

Then he walked out of the store with the pair of pants and disappeared before the surprised store owner could think of anything to say.