what happened when the Indians attempted to market their pearls collectively?

Juan Tomas warns Kino and Juana to get the best price for the pearl, and tells him how their ancestors got an agent to sell their pearls, but this agent ran off with the pearls. Kino had heard the story told as a warning of punishment against those who try to leave their station.

From the text:

"Before you were born, Kino," he said, "the old ones thought of a way

to get more money for their pearls. They thought it would be better if

they had an agent who took all the pearls to the capital and sold them

there and kept only his share of the profit."

Kino nodded his head. "I know," he said. "It was a good thought."

"And so they got such a man," said Juan Tomas, "and they pooled the

pearls, and they started him off. And he was never heard of again and

the pearls were lost. Then they got another man, and they started him

off, and he was never heard of again. And so they gave the whole thing

up and went back to the old way."