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 top combines a few of the biggest trends of the moment (extra-long sleeves, choker details, and an out-of-the-box twist on the classic button-up), it's only a matter of time before it goes viral. For this Pixie Market shirt, that time is now. There are few fashion triumphs greater than tackling three of-the-moment styles at once, which might explain why this top sold out in a flash online and already has a lengthy wait list of shoppers anxious for its much-anticipated return.This top doesn't come cheap, but for $112, you get a shirt that's basically an outfit in itself. Simply throw it on with a pair of jeans and white sneakers, and you've got a no-brainer look that still gives off the illusion that you spent hours deciding what to wear. If you don't mind waiting for this sought-after blouse, click through to get your name in line. And if hanging around for the purchase isn't your style, feel free to shop these similar options in the meantime.