There are three tiers of Bounty Hunts. Although you get some nice gold points for each bounty, you'll really appreciate the experience points you get for each promotion. A Novice Bountyhunter gets 40000 XP, a Journeyman Bountyhunter gets 80000 XP, and a Master Bountyhunter get 1.2 millionXP. Yeah, this is probably a mistake, but no one's complaining.
A particularly sneaky, though not outright dishonest thing to do is to leave at least one body of each type of Monster unlooted. If you get a Bounty Hunt for one of those then you only need to go back and clean it up. This is extremely helpful if you have already exterminated all of that type of Monster and would otherwise be out of luck unless that area re-spawned.