I’ve kept a price book for about 10 years. If you’re serious about getting control over your budget, a price book is absolutely necessary. It allows you to buy only the cheapest items at each store, and provides the information you’ll need to evaluate unadvertised sales and unexpected sources of goods, like garage sales and salvage stores (yes, I’ve purchased new grocery items and household supplies at garage sales. You never know what you’ll find). Recently I found store-brand disposable diapers at a salvage store. We use these at night and for traveling so I whipped out my calculator, checked my price book, and found that the per diaper price was cheaper than the cheapest disposables at Wal-Mart. I stocked up. Knowledge is power!
I keep my price book in an Excel spreadsheet, which is formatted to automatically calculate unit price. I sort items alphabetically and by category, one category per page. With the exception of clothing, which I rarely buy new anyway, I keep track of prices for most consumable products we purchase. This includes food, office supplies, personal care products, household supplies (paper towels, light bulbs, etc.) oil and filters for the car, and pet food.
This is the baking supply page of my price book. It includes the product name, any notes such as flavor or brand, the package size, the price, the unit price, the store where it was purchased, and the date. The date is important because over time you’ll notice sale trends (EX: nuts and baking supplies are always cheaper at Christmas. Buy in bulk and freeze them). The yellow line through the “cornmeal” entry means that I need a current price for that item.
After all of these years of tracking prices, I’ve narrowed my shopping down to two stores: Aldi and Wal-Mart. I always buy their generic products because they’re consistently the cheapest. Occasionally another local store will have a really phenomenal sale that beats them, but this is unusual. When it happens, I buy a lot! I have a list of items to buy at Aldi in my HMG. If any of those items is on my weekly grocery list, I check it off with my dry erase marker, and take the page with me so I remember to stop at Aldi before I head home. Aldi is right across the street from Wal-Mart, so it’s very convenient.
If you want to make your own price book, you will first need to make your pantry list (see The Frugal Pantry). Once you have this list, you’ll know which items you need to get prices for. Tracking prices of other household goods is more challenging, because you may not purchase them as regularly. I still add items to my price book that I’ve forgotten about (humidifier filters come to mind).
When you set out to research prices, don’t take your kids, and don’t make special trips! This wastes extremely expensive gasoline, and making a price book is a gradual process that takes time. I get my prices from my receipts, sale flyers, and by simply jotting down prices as I do my regular grocery shopping. It takes a few trips, but it makes the process less overwhelming. If you have friends who also want to make price books, you may want to assign each of them a list of items, and make it a cooperative effort!