One secret to savvy shopping is knowing when to really stock up on something. Your "stock up price" for an item should be that magic price at which you will buy enough to last you for a while. You want to wait for the price to hit rock bottom, but it's hard to know when that is happening if you don't do your homework. So here are some tips on how to decide when to buy and when to pass. (Because there is nothing worse than stocking up on a product only to see it on sale for cheaper two weeks later).
First, you don't have to have a spreadsheet of prices for everything in your pantry. I would pick a few of the products that your family uses the most and start with those. First look at what you've been spending on those products and get a general idea of what the average price is. Next watch the sale ads for special prices on those items, making a note of the lowest prices you see over the course of a month or two. You should see a pattern and be able to identify what the true "rock bottom" price for that product is. For some products you will want to factor in coupons, as well. Finding your stock up price doesn't mean that you will only buy the product when it hits that price, it just means that when it DOES, you will consider buying extra to save in your stockpile.
For example, my stock up price for toothpaste is $0.00...because I know that there will be times where I will be able to get toothpaste for FREE with a sale plus coupons. I still do occasionally buy toothpaste...usually I try not to spend more than $.25-$.50 on a tube. But I don't buy 3-4 tubes unless I'm getting it for free!
My stock up price for Diet Coke 12 packs is $2.50/pack. I have learned that it is VERY rare for Coke 12 packs to be priced less than this. Since the regular price is more than $4/pack, when the price hits $2.50 I buy up as many as I can find so I don't get stuck paying regular price when I run out!
Bottom line is do your homework so that when you buy 12 boxes of cereal at Hy Vee this week, you know that you are getting the very best price on them!