EDIT:
Original:
Source: http://www.bethblog.com/2015/04/23/skyrim-workshop-now-supports-paid-mods/
Refund policy:
Source: http://steamcommunity.com/workshop/refundpolicy
FAQ:
Original:
We’ve had a long and excellent relationship with our good friends at Valve. We worked together to make the Workshop a huge part of Skyrim, and we’re excited that something we’ve been working together on for a long time is finally happening. You can now charge for the mods you create.
Unlike other curated games on Steam that allow users to sell their creations, this will be the first game with an open market. It will not be curated by us or Valve. It was essential to us that our fans decide what they want to create, what they want to download, and what they want to charge.
Many of our fans have been modding our games since Morrowind, for over 10 years. They now have the opportunity to earn money doing what they love – and all fans have a new way to support their favorite mod authors. We’ve also updated Skyrim and the Creation Kit with new features to help support paid mods including the ability to upload master files, adding more categories and removing filesize limit restrictions.
Source: http://www.bethblog.com/2015/04/23/skyrim-workshop-now-supports-paid-mods/
Refund policy:
Steam Workshop Refund Policy
1) Valve offers this refund policy exclusively for initial purchases of user-generated content made directly via its Steam Workshop page. In particular, this refund policy does not apply to purchases of tradable Workshop Items on the Steam Community Market, to transfers of items between users via the trading system or to in-game purchases of Workshop items.
2) In order to request a refund, click the "Get Refund" option on the item's Workshop page, which is accessible from your Steam inventory page (in the Steam Client, select View->Inventory from the top menu). Refund requests must be made within 24 hours from the purchase of a Workshop item. The remaining time for an individual item is displayed on the item's Workshop page.
3) Once your refund request has been submitted, you will lose access to the content for that Steam Workshop item and any other Steam Workshop items associated with the refunded transaction.
4) Refunds will be credited exclusively back to the Steam Wallet from which the original purchase was funded. For reasons of fraud prevention, your Steam Wallet will be credited for the transaction within two to three days from the time you submitted your refund request.
5) Valve may restrict an individual user's eligibility for future refunds if there are indications of an abuse of the refund system. In this case, the restriction will be clearly communicated to the user and only apply to later purchases.
The terms of the Steam Subscriber Agreement (http://store.steampowered.com/subscriber_agreement/) apply.
Source: http://steamcommunity.com/workshop/refundpolicy
FAQ:
For Creators
Q. How do I set the price of my item?
A. When posting a new mod or item to the Skyrim Workshop you’ll be presented with some controls and a checklist to get your item listed for sale.
Q. How much should I charge for my item?
A. The appropriate price for your mod, map, or item will depend on a number of factors. Here are some things to think about:
1. How many similar items are already available for sale or for free?
2. How much unique content have you created? Is this something which is hard for others to do?
3. How many hours of playtime does your experience offer?
Q. Can I change the price of my item once posted?
A. Yes, but there may be limitations on how frequently you can adjust your price.
Q. What if I see someone posting content I've created?
A. If someone has copied your work, please use the DMCA takedown notice.
Q. Can I include someone else's mod in my mod?
A. The Steam Workshop makes it easy to allocate and approve portions of your item’s revenue with other collaborators or co-authors.
Q. Can I delete my Workshop item?
A. You can stop selling and delist your Workshop item, but it cannot be deleted. If there are customers have purchased your item, they will need continued access to the mod as well as your Workshop page so they can reference the items they have purchased.
Q. How do I get paid for sales of my item?
A. Please see Workshop Revenue FAQ
Q. Can I sell the mods I’ve made for other games in the Steam Workshop?
A. It is up to the developers or publisher of each game to decide if paid Workshop mods are appropriate for their game. You will only be able to sell mods for a game in the Steam Workshop if the developers have enabled that functionality.
Q. Can I sell a mod that contains artwork or content from another game or movie?
A. You must have the necessary rights to post any content that you post to the Steam Workshop, whether it is for sale or not. If you upload copyrighted content that you or your contributors do not have the rights to distribute, then you may forfeit all earned revenue from the item, may be liable for damages and compensation, and may be banned from future participation in this Workshop or the Steam Community in general.
For Players
Q. Can I get a refund?
A. If you discover that a mod does not work for you, or does not meet your expectations based on the description of the mod, you can get a refund within 24 hours of your purchase. You can view the full refund policy here.
Q. How much do paid mods cost?
A. The prices for mods are set by their authors, and depend on their size, complexity, and the type of content. Unique quests that may contain dozens of hours of playtime will probably cost more than a new hat for your character.
Q. Where can I find the mods I've purchased?
A. In your Steam Inventory
Q. Why can't I rate all the mods I see in the Steam Workshop?
A. For paid Workshop items, you need to have purchased the item before you can rate it.
Q. What happens if a mod I bought breaks?
A. Sometimes one mod may modify the same files as another mod, or a particular combination of mods may cause unexpected outcomes. If you find that mod has broken or is behaving unexpectedly, it is best to post politely on the Workshop item's page and let the mod author know the details of what you are seeing.
Q. Couldn’t I already buy items made in the Workshop?
A. While a few games support voting for items to be integrated by game developers and sold in-game as items or DLC, there hasn’t until now been a way to buy items directly through the Workshop. With paid mods and items becoming available for sale on the Workshop itself, it means more high quality items, mods, and experiences can be made available for your favorite games.
Q. How do I play a Skyrim mod I’ve purchased or subscribed to?
Once you’re acquired a new mod, simply launch Skyrim from your Steam library. When the launcher appears, you’ll notice status text on the lower-left as your game downloads and installs or updates new content. Once that’s done, you’re ready to go!
You can also use the “Data Files” portion of the launcher to activate or deactivate specific mods. If you’re unsure how to access new content in-game (such as figuring out which in-game vendor carries Lydia’s new hat) it’s best to check the Workshop page for that mod to see if the author has provided any clues or instructions.