> why are you not buying in large bulk and saving?

Although I'm probably not thinking of a few things, I do buy basically every nonperishable in bulk. I buy paper towels, toilet paper, double-edged razor blades, toothpaste, laundry supplies, and shower supplies at most twice a year. It's not that hard as long as you find SKUs that you like and have somewhere to store them (and I live in a tiny San Francisco studio, so most people should have plenty of room).