The desire for skins that are no longer obtainable through Riot—such as the Original Championship Riven or the PAX series—has birthed a massive secondary market. However, "buying" rare skins from third-party websites or individual sellers is fraught with danger.
For most players, the safest and most legitimate way to acquire rare skins is through Riot’s internal systems: buy rare league skins
Almost any skin in the game (excluding a few ultra-limited ones like Victorious or PAX skins) can technically be "rolled" by combining three skin shards. This is a game of pure luck and deep pockets. The Dark Side: Third-Party Markets The desire for skins that are no longer
Riot periodically rotates "Prestige" and "Hextech" skins into the Mythic Shop. While these require Mythic Essence (earned through play or loot boxes), it is the only way to officially "buy" skins that were previously retired. This is a game of pure luck and deep pockets