We are working on changes to make farming the same level less attractive.
One way to deal with it:
Replaying story scenarios on any difficulty would reward 100g maximum, the idea being that the official adventures exist for people who primarily want to experience the scripted story and scenarios, and to acquire items from specific adventure decks to take on those particular challenges, while still getting some form of monetary reward.
Quest mode, on the other hand, could pay out up to 200g at legendary difficulty, because each run is randomly generated and thus there's no specific "easy mode scenario" to farm. People who want to earn gold above all else would be directed towards this option.
Edited by Feywood, 06 May 2016 - 10:36 AM.