Probably: Farm gold and buy of Gypsy Vagabonds in the wandering gypsy camps of Ilshenar (not the 4 permanent spots).
Next best: farm something that drops gems, and use the EC client to speed looting. My guess is that the 3-gargoyle pass south of compassion (SE of the permanent gypsies by the Central Ilshenar entrance) probably would have a quicker turnover ratio than farming dragons (since you don't have to dodge greater dragons that way). Another spot would be the stone gargoyles around Chaos gate, and down the edge of Ilshenar (where there is a somewhat phallic-shaped box canyon that spawns 3 stone gargoyles). If you had mining and a fire beetle, you could probably ride down there, stack the ore off the corpses, and smelt the ore before you left.