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.Okay, we get it. It's only January. But hear us out: If a winter escape to warmer weather isn't on your horizon, that's okay. Getting a head start on swimsuit season never hurt, especially when you're trying to snag one of the most coveted items. You'll thank yourself once it's finally time to hit the beach.We already know that the one-piece is back with a vengeance, but swimwear brand Solid + Stripe's famous version, the Anne-Marie, has taken the newly revived trend to the next level. If the suit looks familiar, it's probably because you've seen it on every celebrity, blogger, fashion editor, and influencer you follow on Instagram — think everyone from Natalie Suarez to Beyoncé . And at only $140 to $158 (depending on the print or colorway you select), it's no surprise that it's in constant demand on the brand's website.Since you're bound to be dreaming of sunny days as the winter weather rolls in, why not brighten things up by shopping the must-have swimsuit for yourself? And if it's already sold out by the time you're reading this, we've rounded up some equally cool alternatives to satisfy all your poolside needs. Just think: Your Baywatch-inspired Instagram shoot is about to reach new heights.