Tragic Hero or Tragic Failure?

" Linda: He loves you Willy!
Happy: (deeply moved). Always did, Pop.
Willy: Oh Biff! (Staring wildly) He cried! Cried to me. (He is choking with his love, and now cries out his promise.) That boy- that boy is going to be magnificent! (Ben appears in the light just outside the kitchen.)
Ben: Yes, outstanding, with twenty thousand behind him!"

This is the point in the novel where Willy officially decides to kill himself. At this point he realizes that Biff actually loves him. He realizes that Biff doesn't hate him for the affair. Willy finally releases himself from the guilt he feels for the affair, and for sending Biff down the path that he has been traveling on since that night. Biff accepts that his failure is his problem, not Willy's. So Willy decides that with his new knowledge that he can better help his son by killing himself, he can give his son one last gift, knowing that Biff will take responsibility from now on. Does this make Willy a tragic hero? Or is he a seriously misguided crazy person talking to visions and living in the past?

First of all, I hate Willy. And I hate this Ben character that keeps showing up and rattling on about Alaska and the diamonds in the African jungle. They both have this shared sense of fame and fortune and both count a man's worth in money and how well the man is liked. One doesn't simply walk into a jungle at seventeen then walk out rich at twenty one, that's baloney. And even if he did, would that make him happy? The both of them keep pushing this concept of 'making your fortune' on Biff as if living a happy life isn't enough, you must be rich and like also. This is certainly a flaw, but I don't see how it is tragic, since a tragic flaw is usually a good quality that goes awry. This flaw is already awry.

But Willy sacrifices his own life to offer his son one last chance to make a life. Is that selfish? Or is it heroic? And is Biff even grateful? Wouldn't a son rather have his father alive, even if it meant less money?
I can't tell. My prejudice makes me think he's a tragic failure, but that's just me.