Goat
If you are really on the cutting edge, you may be looking for pre-owned, unused, and collectible shoes. You can either attend a Sneaker Con show or you can browse from the comfort of your own bed and find them in GOAT (Greatest of All Time), a massive marketplace for Pre-Owned (or new) shoes. The Company has been so successful since its founding in 2015 that they have raised a boatload of cash and even purchased Flight Club, the first mover in this space. You can buy things offered straight away, follow release dates of popular shoe series, or track shoes that may be offered in the near future. You can filter the selection by make, model, or even color. I have my eyes on some Air Jordan 3 Retro Flyknit Black, but I'm waiting for the price to come down from a whopping $870!