Starting a price book means never having to head-slap yourself for paying too much

A price book is a notebook you organize to suit your shopping habits, in which you record a product's price per ounce (or serving, if you prefer), the brand, size of the container, store name and date. A cold cereal category might look like this:

Brand Name	Package Size	Store	Date	Price per Oz
HCF Corn Flakes	18 oz	East Side Grocery	04/06/12	0.087

(If using software to make your price book, I just realized you need to set your number format to text so it won't automatically round your price per ounce to the nearest penny.)

When you're first starting a price book, I recommend going to the store without children, if at ALL possible. At least for me, when there's math involved, it must have my undivided attention if it's going to be anywhere close to accurate. Use a calculator to figure price per ounce or serving; don't trust the handy-dandy price per ounce on the shelf tag that some stores provide. That number is sometimes wrong, so figure it yourself.

Calculate the prices of everything in a certain category that you are sure your family will eat, and then decide on a maximum price per unit (price point) you're willing to pay. For cold cereal, I don't pay more than 11 cents an ounce. Don't assume that larger quantities (such as huge bags of cereal) are cheaper; that's what manufacturers want you to assume. Those bags sometimes cost double what smaller boxes cost. What happens when I don't find cereal that is less than my highest price point? We don't have cereal.

Keeping a price book can help you track store sale cycles (usually 3 months). It can also save you time at the store if you're buying loss-leader items, because you'll know in advance if they're good buys for you. Loss-leaders are advertised sales, usually on the front and back pages of a sales circular, on which the store takes a loss. They're hoping that great deals will entice you into the store and you'll spend money on other things so they'll recoup that loss, but an ad scheme is no match for a smart shopper with a price book.

A few of my price points:

• Cereal: 11 cents an ounce
• Fresh fruit: $1 a pound
• Cabbage: 33 cents a pound
• Potatoes: 30 cents a pound (good cheap food, but “junk” food in my book)
• Ground meat: $1.50 a pound
• Bone-in meat: $1 a pound

Just a note: adjust your price points with inflation. The cost of everything has gone up about 33 percent recently, and it's only going to go higher as gas prices increase.