If you ever think or know you could have gotten a better price on an online purchase, sign up at Paribus.co and they will help you! Once they have access to your email receipts they will track the prices of the items you purchased. If they find a lower price, within the retailer’s allowed adjustment period, they will email the retailer and request a price adjustment. This refund, which is usually honored, will be issued back onto your credit card. Get all the details on the site.