Quote 4
CHARLEY: You want a job?
WILLY: I got a job, I told you that. [After a slight pause] What the hell are you offering me a job for?
CHARLEY: Don’t get insulted.
WILLY: Don’t insult me. (Act 1)
Willy has always tried to act like he is cooler than Charley. In reality, though, he's always been really jealous of his neighbor. When Charley offers Willy a job, it hurts Willy's pride. If people know that he's working for Charley, then there will be no denying the fact Charley has done better in life—and Willy's delusional pride just won't allow that.
Quote 5
CHARLEY: I offered you a job. You can make fifty dollars a week. And I won’t send you on the road.
WILLY: I’ve got a job.
CHARLEY: Without pay? What kind of a job is without pay? [He rises] Now look kid, enough is enough. I’m no genius but I know when I’m being insulted.
WILLY: Insulted!
CHARLEY: Why don’t you want to work for me?
WILLY: What’s the matter with you? I’ve got a job! (Act 2)
Despite the complete absurdity of refusing Charley's job offer (considering his financial circumstances), Willy's pride prevents him from accepting. Willy is determined to pretend like he doesn't need Charley's help even while he's asking for it.