Mine uses coupons too. But he’s very careful as not all coupons are a deal.
Mine can quote the price of everything on the shelf he buys.
He knows coupons and versus regular price and he also watches the changes in the size and weights of boxes, packages, containers and cans.
He told me that my Walker Shortbread cookies went up 50 cents per box since Christmas, and by God, he’s right.