Why is Willy interested when Biff mentions Bill Oliver?
Willy desperately wants his son Biff to succeed. When Biff mentions his idea of borrowing money from Bill Oliver so start a sporting goods store, Willy is delighted because it shows the kind of enterprising spirit he has always expected of his son. Biff's idea of borrowing a large sum of money from a man who is only an acquaintance is unrealistic, and his father's encouragement to go ahead with the idea is equally unrealistic. In fact, Willy may seem even more unrealistic because Biff only wants to ask for $10,000, while Willy has such an inflated opinion of his son's potential that he thinks Biff should ask for $15,000. As it turns out, Biff is humiliated when he goes to Oliver's office. Biff realizes as he is sitting waiting for long hours to see his former employer that what he is doing is crazy and that his father must be crazy to believe in it with him. It turns out that the reception at Bill Oliver's office is a blessing in disguise. It forces Biff to wake up to reality; And Biff would like to make Willy face reality to. Biff likes reality because it represents freedom. Reality may be good for Biff, but it is unacceptable to Willy, who is too old to change. It is significant that Biff wants to open a store that sells sporting goods. This seems to illustrate that his love for a physically active outdoor life is involved in the compromise he is trying to make between his real identity and Willy's unrealistic expectations. From what we learn about Biff, it seems unlikely that he would be a successful shopkeeper. He is hoping Bill Oliver won't remember he once stole a box of basketballs--but if he had gotten to talk to Oliver and had mentioned sporting goods, it could have triggered his former employer's recollection of those missing basketballs and his suspicion that his former shipping clerk stole them.
Willy thinks that Bill Oliver can fund Biff's proposed sporting goods store, and give his some a chance at a career and some direction in his life.