I am a "stocker upper....", but when is enough is enough?

Not at all. I bulk buy too where i can, as it makes life easier. When you have four young children under the age of two, even with a car, you can't just nip to the shops to buy milk. Going to the shops is a practically military planned operation. I have a pantry just off my kitchen, and i make sure it's fully stocked with everything. If we ever can't go out, my babies will never want for anything, and thats the main thing.