I really enjoyed taking all the gold from Might Heroes with just a leather armor. Their desire for an armor was so high, I only needed to sell a leather armor to take all their remaining gold. I really like drying up parties when they need items the most hehe.
If you still having trouble with gold, just wait until one of those parties that failed a quest show up. Then just take all their gold with cheap items. Who cares if they get wiped out anyway.
