Based on the text of The Pearl, how was the pearl valued?

In chapter four, John Steinbeck tells us about the pearl buyers. We learn that the pearl buyers used to be individuals who bid against each other, therefore sometimes driving the price up too much and overpaying for a pearl. Now, they take advantage of the villagers by all working for the same man and therefore controlling the price they will pay for a pearl.

Now there was only one pearl buyer with many hands, and the men who sat in their offices and waited for Kino knew what price they would offer, how high they would bid, and what method each one would use.

Kino believes the pearl he found has a very high value. He takes it to a pearl buyer, who has already been instructed to undervalue it.

"I can give you, say, a thousand pesos."
Kino's face grew dark and dangerous. "It is worth fifty thousand," he said. "You know it. You want to cheat me."

This leads Kino to journey to the capital in an attempt to get a fair value for the pearl, a journey that ultimately results in the death of his child. In that sense, the "evil" pearl was worth much more than a monetary value.