This bonus content is disappointing, lazy and cheap from Bioware. That's my opinion.
I agree, from what I see it really doesn't seem like it's worth the extra $.
Skyhold Throne: Nice if you're into sitting inside a giant lizard skull, but otherwise...
Mounts: A lot of these in the game already, and all they're really used for is getting to a point that you've already explored quickly.
Soundtrack: This one actually has a bit of perceived value, but it doesn't justify the total expense imo.
Armor & Weapons: The games crafting system makes these a lot less vital than they might be otherwise. It's not like Mass Effect 3 where the DLC weapons and armor had unique stats and functions that you couldn't find anywhere else, here one sword can be made to swing just as well as another. You'd basically be paying for the design of the weapons and armor more than anything else.
MP Chest: As has been said there probably isn't anything that you can't get here with some good old grinding.