Do you know about this little-known tip?

Costco Is Now Offering a Gift Registry Service

We all have a superhero moment. The time we snagged a package of Kirkland Signature AA batteries just in time for a summer camping trip. That day we scored an on-sale blender a week before a big dinner party with Gazpacho on deck. Finding that perfect birthday gift for your nephew that also happens to be part of a special President's Day Weekend offer.

But what about when your heart sinks as you realize the expensive vacuum you bought last week is now being sold at a 30% markdown? Well, leave it to the warehouse club to make it easy to reclaim the difference. If you bought something on and notice a price change within 30 days, you're in luck.

As Reader's Digest points out, use the "request a price match" online form and you can get the difference in what you paid for it vs. the sale price refunded. The website states that credits are typically issued in three-to-five business days. Worth noting: Costco only will issue a credit for items bought on, it won't match the price of other retailers.

WATCH: Great Cheap Wines at Costco to Stock Up On During Your Next Trip to the Warehouse Club

But what if you bought something at a Costco store and see it sold at a promotional price shortly thereafter? "If you purchased the item at a Costco warehouse location, please inquire at the membership counter at the Costco location where you made the purchase," a statement explains on the site. While your club may not offer price matches, it can't hurt to ask. After all, if they do, that Costco pizza pie may be on them this time.