After the kims were able to secure a working position for the perks, both families were benefited. The Parks benefited from the service of the Kims, and the Kims from the wealth of the Parks. 

The Kims were ideal for the Perks since they knew not to cross the line. In this scene, the Kims think that the Parks are nice because they are rich. However, in reality money is just the iron that irons out all their creases.