A bad move. Mods are for share, not for sell. Please donate for creators if you think they worth it.
I won't judge someone who puts their mod to sell, just make sure you are now handling costumers, not fans and followers. And only 25% of the sale will be for you, at respect and reputation expenses.
The minds who come with this idea don't have a clue about what modding is. Also, without modding (unofficial patches, SKSE, addons and huge content added), Skyrim would be a below average game by today standards, instead of a live and active gaming community, still developing and bringing the game to the new generation.
Sign the petition against Steam paid modded content system here: https://www.change.org/p/valve-remove-the-paid-content-of-the-steam-workshop