Have you ever gone to the grocery store and wondered why prices on the same items change so much each week? A box of pasta may cost 79 cents one week and $2.39 the next. A bottle of juice that costs $2 today may cost $4.29 just a few days from now. Most people accept these price fluctuations as normal. Many don't even notice them at all.
Why do prices at the grocery store change so much in a short period of time? Grocery stores sales run in 12-week cycles. Most everything in the store is at its lowest price point just once every 12 weeks. Throughout the rest of the cycle the price may fluctuate a bit, but it won't go to its rock-bottom low again until the 12-week cycle is complete.
You might be thinking what I thought when I initially learned this valuable piece of information: "What if I had just bought more pasta last week when it was 79 cents?" Better yet: "What would have happened if I bought enough boxes of pasta to last my household 12 weeks?" I'd save $1.60 on each box. If we ate pasta once a week for the next 12 weeks, I would save $19.20 by buying all 12 boxes in one trip when the price was low.
Granted, this approach goes against everything we typically do as shoppers. When it's time to go to the store, most of us look around the house, see what we're out of, and then go to the store to buy it. But the problem with this is that it's impossible for every item on our list to be at its lowest price point, since different categories of grocery items operate on different pricing cycles. That's part of the grocery store's marketing plan. Stores know that if shoppers come in for a sale item, it's likely they will buy many other full-priced items.