Keys that were already sitting in user inventories prior to this update were exempt from the restriction. They remain fully tradable and marketable to this day.
To acquire a legacy, tradable key, you cannot use the in-game store. You must rely on secondary peer-to-peer markets. 1. The Steam Community Market how to buy tradable keys csgo
Because of their finite nature and historical use as a stable, cross-border trading currency, legacy keys command massive premiums compared to the standard $2.50 USD in-game equivalent. 🛒 Methods of Acquisition Keys that were already sitting in user inventories
To understand how to buy tradable keys, one must first understand why they are so distinct from standard keys: You must rely on secondary peer-to-peer markets
The most straightforward and secure method to buy a tradable key is directly through the official Steam platform. How To Buy CS:GO / CS2 Keys? - SellYourSkins
On October 28, 2019, Valve disabled the trading and marketable status of all newly purchased container keys to combat large-scale fraud and money laundering.