Ok for some game DLCs honestly suck. First coming to mind is COD(I kinda hate it but that's just my opinion). The game itself isn't worth the price and there's a season pass having 4 DLCs by the same price of the game. -_- And let me don't start with weapon packs (not the weapons for F2P games) and horse armor of other games.
About the value of the good DLC i think it depends on size itself. The Binding of Isaac(Vanila) which was a little flash game had price tag of 5$. It's DLC which was as half as big as the vanila was sold for 2$. That's a good DLC at it's finest. Other exsample: Fallout 3 and Skyrim. Expensive yeah but also valueable. You have a big world and you have bigger world.
Please remember that it's just my opinion.
Honestly, I think that if someone makes DLC, they should have justification for making the DLC. For example: "This map pack was made because users were not satisfied with the amount of maps originally included in the game," or "Due to the game only having a multiplayer mode, we've added a DLC single player mode to add to the game's experience."
If someone doesn't have a reason (other than "to make more money" or "because I felt like it") to make DLC, then they shouldn't make DLC. If you wanted something put into the final product, you should have done that BEFORE you released it.
Don't have enough time to add the content before the release? Delay the release.
Don't have enough money to make the content? Save it for another game.
Don't have enough people to make the content? Get more people, delay the release, or save it for another game.
It's preferable to take your time, and make the game as good as you can as opposed to rushing, and releasing something half-finished. That's an important lesson that everyone should learn. There are a few people on this forum site that should learn that. I won't mention any names here.
Although that... thing... named (something with five letters, two of which are U's) should have learned that before getting banned.
