BIFF: Pop! I’m a dime a dozen, and so are you!
WILLY (turning on him now in an uncontrolled outburst): I am not a dime a dozen! I am Willy Loman, and you are Biff Loman!
– Arthur Miller
Death of a Salesman, Act 2. Willy’s sudden outburst of rage when son Biff says they are "a dime a dozen" may stem from his narcissistic personality. Willy with his foolish pride has a need to feel that he and his sons are special. He refuses to believe Biff’s characterization of the Lomans as being no better than the next guy. It is yet another example of Willy deceiving himself.