After being away from home on business the week before Christmas, Tom thought it would be nice to bring his wife a small gift. "How about some perfume?" he thought. A cosmetics clerk showed him a bottle that cost about $50.

"That's a bit out of my price range," Tom said. The clerk returned a moment later with a smaller bottle costing $30.

"That's still quite a bit," he groused. The clerk brought out a tiny $15 bottle.

Tom grew agitated. "What I mean," he said, "is I'd like to see something real cheap."

The clerk handed him a mirror.