How does Marlowe utilize the bargaining process he learned from King? Chapter 17

In Chapter 17, one of the men in Marlowe’s detail asks if he could sell a pen to Torusumi for him. The man says that since Marlowe is friends with the King, he might be able to get a better price. Marlowe hesitates and then asks how much he wants for it, and the man tells him $65. Marlowe takes the pen to Torusumi, who immediately offers him $75. Remembering how the King did business, Marlowe haggles with Torusumi until finally they agree on $120. Marlowe gives the soldier the $65 he asked for and keeps the rest.