The realtor I used to buy my last house does it as a hobby. She also did one of the most ethical things I have ever seen, and only took her commission at our initial offer, she wouldn't take commission on any of the escalation clause raises.
It at least makes it so that the buying agent doesn't profit from any additional upward movement in price. I guess it's about as good as you can do with such a screwed up incentive structure.
Hi, can you help me get the lowest price possible on a house? Sure, and the lower I can get your price, the less money I make, how does that sound?
Oh, and add to that, not only will I make more if you make more, but offering a higher amount will close the deal faster so I can move on to the next person.