Who says there’s no such thing as free money? Those who have mastered the art of coupon shopping know there is. To them, that little scrap of paper that says “.75¢ off” is a real opportunity for big savings; they see dollar signs, not added hassle to their shopping routine. Therein lays the rub: The provisos that accompany coupons — or the effort involved in using them — often give them a stigma, which leaves people with a why-bother mentality.