I wouldn't say it's normal in that it happens all the time. But if I'm going to make the trek to the Capital, I'm going to Costco, and if I'm going to Costco, I may as well pick up a hundred rolls of Brawny for more than one person. My parents used to do it too. Or rather, my mom used to tell my dad "since you're going anyway," and hand him a list. It was pretty hilarious.