My friend and I joined a weight-loss organization. At one meeting the instructor held up an apple and a candy bar.  

"What are the attributes of this apple," she asked, "and how do they relate to our diet?"  

"Low in calories" and "lots of fiber," were among the answers.  

She then detailed what was wrong with eating candy, and concluded, "Apples are not only more healthful but also less expensive. Do you know I paid fifty-five cents for this candy bar?" We stared as she held aloft the forbidden treat.  

From in back of the room a small voice spoke up. "I'll give you seventy-five cents for it."