is how much you have negotiated your salary?
I have one main principle regarding this story: you are asking for an amount. If you are receiving what you have asked for, why are you complaining. If the offer is lower, why have you accepted it?
On the other hand I know a lot of Indians or Iranians that are paid better than me. So, maybe is not the nationality. Each of us consider himself the most beautiful/handsome, the smartest, the most skilled etc. person. Maybe is not true, have you think about this??