I guess the number one question is why would anyone want to have a grocery stockpile? Well, hmm..... it keeps you from going into a grocery so often. Every time you enter a store you will come out with more than you planned to buy. There is always one or two things you spot in the store that temps you to buy it. List or no list, people tend to pick up one or two extra items. Stores are designed that way.
How many times have you gone into a store to buy milk and bread only to come out of the store with several bags of groceries? It's much easier and cheaper to go to your own personal little grocery just a few steps away from the kitchen.
Another reason is that it's not always convenient for everyone to go to the store. Like me, I don't have a car so I'm dependant on someone taking me or being a chauffeur for my SIL. If I can't get a ride when I need groceries then I am forced to do without. If I have a well stocked pantry this isn't a problem. I can make do with what I have.
Then there are the natural disasters that happen. In a short few months, the Louisville area went through a wind storm, an ice storm, and a flood. The first thing anyone does when there is a natural disaster is rush to the store to stock up on foods and toiletries. The shelves are empty really quickly. When the news tells us that we are expecting a major snow storm people start to panic and rush to the store. Pretty soon the shelves are empty of essentials like milk and bread.
Natural disasters in other areas will also wreck havoc with your grocery budget. A flood in an area that supplies corn for cornmeal means that the cost of cornmeal will get higher in our area. An ice storm or hard frost in the area where fruits are just forming buds may mean there won't be as much fruit sold in our area. The cost will skyrocket on fruits. Fires in California can destroy foods sold in this area. A drought in the west can cause the cost of foods like tomatoes grown in that area to cost way more than normal.
Everyone knows the cost of gasoline will have an impact on the cost of foods. If the cost of gas goes higher it's passed on to the consumer. The oil spill in the gulf caused the price of sea foods to rise dramatically, despite the fact that seafood comes from other places like Maine and Alaska. Remember the economic melt down we went through not long ago? Remember what happened to the price of groceries? The rising costs could happen again.
Creating a stockpile of groceries from a store is the modern version of what Grandma and Great-grandma did. They would have harvested and preserved everything the could so it would last until harvest time again. You should harvest foods from the grocery at the lowest price to last until lowest price again.