In John Steinbeck's The Pearl, what does the description of the stout pearl-buyer's trick with the coin suggest about his motives and personality?

The pearl buyer’s trick of rolling the coin through his fingers is symbolic of his “trickery” with money. Kino is aware that the pearl buyers are in league with each other, but he decides to give them a try; perhaps they will unexpectedly give him a fair price. But the buyers have already heard about Kino’s find of the magnificent pearl and have come up with a plan. One buyer will give him one price, stating that it is too big to be easily sold. It would take someone with more money than anyone around the area has, so the buyer declares that it will be difficult to sell. When Kino asks another buyer, he learns that this buyer agrees with the first assessment and finds additional flaws, offering an even lower price. In reality, the buyers are manipulating Kino into accepting a lower price, while they plan to take the pearl to the city and make a handsome profit. This manipulation of the poor people who come to sell their finds is the same way that the buyer plays his tricks with the coin.