The absolute best way to make money from "farming" is to just do the following:
In that order of importance. I usually get 1-2 Mysterious Shards per week running RAR (currently 30m each), and the occasional special dungeon pouch/enchant scroll from special and raids.
Farming chunks is a massive waste of time, and so is running Donegal runs and farming mats. Just do your raids every day, let the gold pile up from selling the drops, and buy the mats you need.
Congratulations, in 2 months or so, you're fully geared, granted you play daily.