My uncle was one of those people who was penny wise and pound foolish. He would buy ANYTHING, if it were on sale, whether he needed it or not. I think he's the reason grocery stores started posting "Limit 3" signs, and he was the guy who'd buy 3, take them to the car, and come back for another 3 of whatever they were. At one time, we cousins counted over 80 cases of pop (at this time, a case was 8 glass bottles) in his basement. Equally, if a thing was not on sale, it was almost impossible to convince him to buy it. Fortunately, underwear and dish soap do occasionally go on sale. He took his dates to the hospital cafeteria, because the food was cheaper there than any other restaurant in town.
But the best story about his cheapness is his gasoline story. When he moved to Washington, DC, someone told him that the taxi drivers knew where the cheapest gas was. So one Saturday soon after he moved, he picked a cab at random and started following it. He followed that cab all day long, and sure enough, in the late afternoon, the cab headed down a small residential street and suddenly turned down one of those driveways that leads to an underground garage. Uncle followed, and sure enough, there was the cabbie getting gas. Uncle pulled up to the pump, and even though he had no cab license and very obviously was in a private car, the guy pumping gas (this was in the early 60s) filled his tank and took his money. It definitely wasn't a public gas station- from the description, it might even have been black market. But for as long as he lived in DC, that's where Uncle got his gas, at lower prices than anywhere else in town.
I have no idea how much money he saved on gas, or how much he spent following a cab around all day. I don't know how he didn't get beat up by a cabbie who didn't want to be followed. I'm just glad that when he left DC, he moved to a very rural town, where all of the gas stations were clearly marked.