Scoring deals at Costco is an art. Smart shoppers know which price tag codes to look for and which delivery deals to take advantage of at the bulk discount store. But when it comes to navigating the food section, there are some tips even longtime members may not know about. A big one concerns brand-name breakfast cereal: When shopping for groceries at Costco, you should leave the cereal boxes out of your cart if you want to save money, according to Yahoo! Finance.

It doesn't make sense to buy perishable items in bulk, but even products with a slightly longer expiration date, like cereal, can end up costing you in the long run if you stock up on them at Costco. The cereal at Costco costs about $0.17 per ounce, which is comparable to the cereal prices you'd find at regular grocery stores on most days. But to reap the most savings possible, you need to visit the supermarket on days when certain cereal brands go on sale.

During different times of the week—usually weekends—many grocery stores will pick a popular cereal brand, like Kellogg's or General Mills, to sell at a lower price. At their cheapest, brand-name cereals can be purchased for $0.13 cents per ounce on sale days, or $1.50 for an 11-ounce box.

While you may be better off buying your boxed breakfast staples at the nearest grocery store, there are still plenty of reasons to shop at Costco. To many loyalists, their $1.50 hot dog and soda combo alone is worth a special trip. The store's addictive pizza slices (which are perfectly sauced by a pie-making robot) and dirt-cheap and delicious rotisserie chickens are yet two more reasons. Just be prepared to show your receipt when you're all done (and don't for a second believe it's because the employees think you might have pocketed something). 

[h/t Yahoo! Finance]