Levels 50+ (55+ for Castle Z and Gustav)
There are quite a few different places to farm Goblins, which are all great for making money. The different places you can go are Glacier/E, Altepa, Jungle, Zitah, Castle Z and Gustav. With Treasure Hunter the goblins drop a good amount of gil, plus you can steal crap from them. The Goblin Armor that they drop will AH pretty well on top of spells that you can AH.