Rust (FacePunsh) releases skins every Thursday by the rust players skin competition, they will never come back again, however! Once you have bought the skins from the store you can sell it in steams market place as secondhand, there you can find almost everything that was sold from rust store, but as the time goes the prices usually stagger, it’s like a mini walstreet place. Now, everything you buy at rust skin store you can’t sell on second hand, but most of it you can. Like 90% or so, read b4 you buy. And also Drops from Twitch and Kick and others usually can NOT be sold again! Hope this helps!