Valve have decided to revoke the ability for users to sell paid mods on the Steam Workshop after the feature received a negative reception from the gaming community.
Articles tagged with 'paid mods'
Dividing Profits: The Community’s Reaction to Paid Mods on Steam

On April 23rd, Valve dropped a bombshell when they announced that community contributors on the Steam Workshop could now put a price tag on their mods. This announcement, however, came as a bit of a shock to much of the community, with many people being in disagreement with the new feature. In this article we take a look at how the community responded to the move.
Valve Is Now Offering Mod Makers the Opportunity to Sell Their Work on the Steam Workshop

Valve is now offering mod makers the opportunity to sell their work on the Steam Workshop, allowing community content creators to earn an income from third-party mods, items and maps.