When did the manager's attitude change? What does this tell us about human nature?

My Financial Career is a (very) short story about a man who nervously walks into a bank, deposits his $56, mistakenly draws it out again, leaves amidst "a roar of laughter," and then vows to never bank again. It's a funny story, and one that has a lot to say about class and money. The man is so nervous to go to bank that he completely messes up the process to the point of being right back where he started. Money intimidates him, as does the upper class, and it shows how the upper class constructs walls against those beneath them.
The manager's attitude begins wary and nearly afraid, as he believes the narrator is a very important person, a detective or someone from a "rival agency." Once he learns that the narrator is none of these things, he "look[s] relieved but still serious."
The moment where his attitude truly changes is when he learns the amount that the narrator wishes to deposit. When he hears this, he deems it a small amount and his attitude changes from wariness and respect to dismissal and disinterest. The manager calls to his accountant "unkindly loud" to finish setting up the account for the narrator; the sum is so small and insignificant that the manager views it as not worthy of his time.
So, what does this tell us about human nature? Well, for one, it posits that rich people only care about other rich people. Secondly, it teaches that people respect wealth and power and don't care for those who have none of it. It also teaches that people judge others by their class, and that they erect barriers based upon class.