The scene where Parker Selfridge is showing Jake the mineral that they are mining for and the whole movie in general symbolizes American consumerism. In the scene, Parker is telling Jake why they are on the panet, to mine the mineral. This particular mineral is very very valuable and justifies the RDA to go to the planet. At this point in the movie, there is no aggression towards the Na'vi but Parker explains that it is very important for Jake to get the Na'vi to leave, hinting that they will have to leave one way or another. Basically Parker wants to mine under the Home Tree which means the destruction of the Home Tree and the relocation of the Na'vi tribe. Parker and the mining company do not care at all for the Na'vi, they want the mineral even though it means the destruction of the Na'vi's home.
American's are shopaholics, we depend on stores and service for everything. Almost no one in the US grow their own food, make thier clothes and pay for somelse to build our homes, cut our hair and fix our cars. Becuase of this consumerism, we are money hungry, many people will choose the way to make an easy buck even if it means the expense from someone else. This movie symbolizes these tendencies of Americans. The RDA are willing to wreck the home and culture of the Na'vi just so that they can make a buck.