Catcher in the Rye chapters 15-16

In chapter 15 of Catcher in the Rye, Holden is at Grand Central Station when he notices someone else with a cheap looking case and this makes Holden remember a story when he was at Elkton Hills, when somebody always switched Holden's bourgeois suitcase with his cheap ones. The moment that really stands out from Holden's story was near the end, when he said that he really started missing the kid. He talks about his feelings afterward, when Holden said this after he moved out, "The thing is, it's really hard to be roommates with people if your suitcases are much better than theirs...It's one of the reasons why I roomed with Stradlater." This moment implies to the reader that some of the little things that characterize a person, like what he wears or how the quality of his suitcase compares to yours, tells you a lot about how another person takes care of himself, how wealthy that person is and that influences what you'd think about them. If there was more explained about the boy that lived with Holden, other than his suitcases, we would know much more about how Holden judges people at first glance.