Shoppers are gravitating to luxury items like never before. Here's the scoop on how to shop authentic accessories online for less. The luxury resale market is booming, and the demand for designer handbags is at an all-time high, with more than a 30 percent year-over-year increase in sales on eBay. But how does a shopper know that the item they are purchasing online is authentic on ebay.com? eBay offers an authenticity guarantee service designed to help customers buy and sell with confidence. With the authentication service, all watches for more than $2,000 are inspected and verified by independent experts, while new and pre-owned handbags sold for more than $500 are vetted and verified by eBay's team of professionally trained authenticators.