Still seems like a rip off to me. CD Projekt are offering two expansions - yes, expansions, not DLC - for $25 total, and they are predicting 30+ hours of content.
Most of the reports I read online, e.g. IGN, Metro, said that Jaws was about 5-6 hours.
They've priced their DLC around this level for a long time--some of the bigger DLCs have been as much as $20 if I remember right. The little item + weapon packs usually have had a $5 price range with larger bundles sometimes as much as $10 (my favorite item pack from BioWare remains Feastday Gifts and Pranks...)
What you also need to remember is that:
- Not as many people will buy the DLC as bought the game. That's simple fact; most people will never buy any add-ons at all.
- It costs a lot of money to make a DLC, especially if you want quality out of it. You have to pay the people who code it, the people who animate it, the people who do the artwork, the people who test it, the--you get the idea. It's expensive. The price point likely is reasonable from the standpoint of a company that knows not everyone's going to buy the DLC but they need to price it high enough to still make a decent profit margin.
- $15 is not an unusual price for BioWare story DLC.
Jaws of Hakkon took me around 10-ish hours to do absolutely everything. People who took less time at it are either better at the game than I am (or playing on casual, or doing speed runs and ignoring enemy encounters), or they didn't do absolutely everything possible within the Frostback Basin. Maybe it would take less time if I didn't insist on reading the codex entries?
If you just play the basic story and don't explore, you probably aren't going to feel you get your money's worth, timewise, out of the DLC. That's okay--if you don't think the DLC is worth the price, you are perfectly welcome not to buy it. Better you not buy it than complain later because you thought it was too short or just not what you wanted.
The Descent is a dungeon crawl. It'll have a story, but I suspect that its story is going to be less important than its exploration and gameplay (I'll see when I buy it next week). It will probably have new crafting materials and interesting loot to be had at the end of the dungeon. It will probably contain lots of lore like Jaws of Hakkon did. We might find that some of the things we learn in the DLC will tie in strongly with the next game. If those aspects appeal to you, then you may wish to buy it even if it does end up being very short. If they don't, you should probably keep your money and vote with your wallet.
The devs don't want you to buy content you don't like. Not only does it spare them complaints about the content, but it also tells them what their playerbase actually enjoys playing, other than those of us who just buy any and all content that they release.
Edited to add: Hope I'm not coming off as rude. I'm basically rehashing what devs have said to players before regarding DLC the player doesn't like. If you think it's overpriced but want it, wait and it'll eventually be on sale. If you don't think you'll like it, don't buy it at all. They want everyone who thinks they'll enjoy it to be able to play and enjoy it, but they don't want people to buy things they don't think they will enjoy. Again, it doesn't just spare them complaints, but gives them a form of feedback on what people will and won't buy, and what we do and don't find interesting. If we buy a lot of a certain type of DLC, there's a good chance that they will create more DLC like it in the future for that game or for other, future games. If we don't buy much of a given DLC, then they'll assume we didn't think it was interesting or it got bad word-of-mouth press. They will make fewer of those kinds of DLC going forward.