Pretty sure devs/admins already know but please be aware the presence of obvious bots are starting to get very common in T3 chaos dungeons.
I would assume they are trading the mats for leapstones on the exchange vendor to sell on AH.
I would suggest making the items of this vendor as roster bound as opposed to tradable would kill off what i suspect is a lucrative market (~1 leapstone @280g per bot per ~2 clears) is best part of 30k gold
Or alternately massively increase leapstone drops which will put a lot more on the market to bring the prices down so its not profitable.
Regardless killing off some of these T3 bots will be great for the game as they obviously have a few resources put into them.