You never want something until you can't have it. So, each week in The Sell-Out, we're getting the scoop from your favorite retailers on what's selling like crazy. Watch this space to find out what everyone's buying, sign up for wait lists, and keep tabs on restocks.When a specific style goes viral, its popularity can often be traced back to a celebrity — or, in the case of these fast-selling shades by Le Specs, two major stars. The Pharaoh sunglasses, in all their metallic-mirrored glory, have been a crowd-pleaser for a while now. At only $119 (which is far less than most other designer specs will cost you), the style consistently sells out, season after season, and has even gone out of stock twice since February.This time, we have Lady Gaga and Justin Bieber to thank. Gaga's worn these shades to three major events recently, including the Superbowl, New York Fashion Week, and her heartfelt tribute performance to David Bowie. Bieber has been sporting them on the road, specifically at his tour stop in Indonesia.