This is the way i used to farm money for my Choppa and Travler Mammuth.
You need lvl 75+. then go to Boaren tundra ( Close to "Fizzcrank" ) and kill "Ragging Bolier".
Hope for "Crystalised fire" to drop ( those have around 30% drop rate ),when u have 10 of these u can make them to a "Eternal fire" and those goes for 100G ea at AH.
Sorry if its a repost.