Overview: The kids contribute to the school's rummage sale. The gang is concerned some of the older stuff will not sell, but Rudy uses slick ways to sell their entire selection. One of the teachers shows Rudy the effects of his actions by giving him a faulty device that ruins his hat versus that shown in a glitzy TV commercial. The lesson is not over, as Rudy, Fat Albert and the others must also head the harbor when Rudy realizes he sold a faulty raft to a boy who cannot swim.