Buying or selling Steam accounts violates the Steam Subscriber Agreement , which explicitly states that accounts are for the personal use of their creator only.

In the context of Steam, "Premium" usually refers to an account that has spent at least (or equivalent) to unlock community features. Accounts that haven't met this requirement are considered "Limited" and cannot add friends or use the community market.

: The original creator of an account can reclaim it at any time through Steam Support by providing proof of ownership, such as original payment methods or CD keys.

Using legitimate Steam Wallet top-ups to unlock premium features.

The listing you mentioned, likely refers to a bulk database of compromised or bot-generated accounts being sold on third-party marketplaces. Engaging with such services carries severe risks: Risks of Purchasing Bulk Steam Accounts