There is significant strategy that goes into the use of our family Costco membership.

We purchase items that guarantee a return in excess of the annual membership fee. This means olive oil, canola oil, batteries, chicken broth, aluminum foil, coffee, and ibuprofen are all “must buy at Costco” items. And it works out great. There’s little waste.

On a recent trip, I succumbed to a perishable. It was a deal that someone who writes about potato chips couldn’t resist: two 20-ounce bags of Natural Planet plain chips (a Shearer’s brand) for under $6.00.

Two 20-ounce bags is 40 ounces, or two and a half pounds. A quart of milk weighs a little less than that. A common grocery store bag is between 8 and 11 ounces, with a typical price point of $3. So $6 was a steal for the volume (roughly a 50 percent discount).

If you’re having a cookout for eleven adults, or you’re hosting a snack party for the local cub scout troop, two 20-ounce bags will disappear in a hurry. For one person, it’s a burden.

Put simply: I broke Costco strategy rules, and breaking the rules carries a punishment. I had to eat every last chip in both bags – before they go bad. The freshness window on a bag of chips is around seven days. So I had to finish the equivalent two family size bags of Lays in a week. Twice!

The chips tasted fine, but the task of finishing the bags took the joy out of consumption. Chips for breakfast? OK. Chips after chips with lunch? Sigh, I suppose. Kids, do you want some chips before bed?  No?!? OK, I guess I’ll just finish them off.

The lesson learned is that a good value loses its luster if you feel sadder during the course of consuming whatever it was that was a good value. So going forward, I’ll be sticking to foods with longer shelf lives, and getting my chips in smaller quantities. And with that, I’m going to heat the 24th bag in my 42-bag stash of microwave popcorn.