Amir, in some twisted way sacrificed his friendship to Hassan so that his father could recognize and favor him. He also engaged in the kite flying contest in an attempt to impress his father. Amir held back the truth about what happened to Hassan because this information was bound to deeply hurt Baba. Amir took his time to accompany his father to the flea market to help him sell some items and get money for their upkeep.
Baba on the other hand accepted the low living standards and worked as a manual laborer in America so Amir could go to school. Despite the hardships they were going through, Baba sacrificed some of the little money he made and bought Amir a car for college. Baba spent almost all his life savings so he could meet the requirements of Amir’s traditional wedding.