<strong>Dear Jill:</strong> I found a great deal on pet food by accident the other day. I went to the grocery store and saw there were several bags of the brand I like. These 15-pound bags were marked down to $11.99, and I had two $3 coupons.

However, when I got to the register, the bags rang up at $4.99. With my coupons, they were $1.99 each. I was really excited about this until I got to the car and started feeling guilty.

Here is my issue: If I took the dog food to the register and it rang up at a higher price than expected, I would have complained. But, when it rang up at a much lower price than it was supposed to be, I silently cheered and paid for it. Do you think this is an ethical issue? What should we do in the future if an item rings up too low? <strong>— Barb F.</strong>

I have to admit I haven’t given much thought to the paradox of pointing out a pricing error when something is priced higher than advertised but not pointing it out when an item rings up lower than expected. I think there are several factors that contribute to this mindset.

First, stores often have unadvertised sales. For example, I recently bought a jar of cumin I needed for a recipe. I wasn’t aware of a sale on spices, and the item was tagged with a standard, nonsale price tag. However, when I got to the register, it rang up $1.50 less than I expected. I assumed the item must have been on sale, even though it wasn’t tagged — and this is often the case. Stores do not always mark every single item that is on sale, even though it would be more convenient for shoppers to see the sale prices as they browse.

Second, clearance prices can be a bit of a wildcard in that stores continue reducing the prices of clearance items to, well, clear them out. Clearances are used to move older product, discontinued product or seasonal items that won’t be carried in-store for future promotions.

The longer an item sits on the clearance shelves, the greater the likelihood is the store will continue to reduce the price in an effort to encourage someone — anyone — to buy it. The store would rather make a little money off the item versus discarding it and making nothing at all.

Knowing this, it’s very likely the store continued reducing the prices on the bags of pet food before you arrived and didn’t update the shelf tag. Certainly, if you want to ask the cashier if the price is correct, you can — but you also run the risk at that point of having the cashier call for a price check, note the shelf tag says $11.99 and manually override the $4.99 clearance price.

Without a physical tag matching the lowered clearance price set in the store’s system, there’s no good way for consumers to know exactly what the price is. From an ethical standpoint, I do not believe there is an issue where consumers must feel compelled to alert the cashier when an item rings up at a lower price than marked on the shelf. Keep in mind when an item’s price rings up lower than expected, it’s because someone at the store manually has changed the price of that item. Contrast that with an item that rings up at regular price when it’s advertised at a lower price — this is usually because of someone at the store failing to enter the item’s sale price into the system.

The unexpected sales and clearance prices we experience at times are one of the pleasures of being a bargain-minded shopper. Enjoy them the next time they surprise you at the checkout — especially if you also have a coupon for the item you’re buying.