Let me see....
Now, to open a chest in an Epic dungeon, you need to expent a Legendary Dragon Key, that you must buy at Zen Market, each one costs 50 Zen - which, in a cost comparison in AD (at an exchange rate of 1 Zen = 500 AD), means that each key has a cost of 25,000 AD - and I'm not even considering the cost of keys in Dollars...
The icing on the cake is that you spend one of these keys to receive at most about 5,000 AD (more often less); one refining stone; some piece of legacy gear that you can no longer salvage to convert in AD - nor sell it at auction house, once they are bonding to your account, being useful only to convert in refinement points; sometimes you get some enchantment (rank 5, or 7 if you are lucky) and, more rarely, a companion, mount or atifact that has a derisory value for sale at auction house...
Simple math - DON'T worth it!! Does Cryptic think we are unable to do calculations ???
And they plundered VIP players, in the process - now you must pay Dollars to be a VIP and in addition, pay more Dollars for the keys ... Isn't fair, I guess. They continue to nerf VIP rewards, again and again...
Comments
One chest, formerly requiring the Epic Dungeon or Daily Dungeon key to unlock, no longer requires a key.
The chest that requires a campaign key, still requires a campaign key.
Other chests, freshly added with the new mod, require keys that can be purchased from the various campaign store or the Legendary Dragon key.
I did expend Legendary Dragon Keys (the sistem advised me about that) opening the final chest at Castle Never (2 keys, once I've opened both 2 chests) and Malabog's Castle (there, to open the 2 chests, I used 1 LDK, and the key done in the Sharandar campaign tree).
I don't know... Maybe it is happening 'cause my keys are old - they were in my bag long time before Mod 15 lauched...