Well, it's on his wiki[1], but most information about this part of the Iran-Contra is questionable, and Ross is very cagey about what he says in his interviews. The last person[2] to really take a deep look into this part of the story killed himself, by shooting himself in the head -- twice.
>According to the October 2013 Esquire article, “Between 1982 and 1989, federal prosecutors estimated, Ross bought and resold several metric tons of cocaine. In 1980 dollars, his gross earnings were said to be in excess of $900 million – with a profit of nearly $300 million. Converted roughly to present-day dollars: 2.5 billion gross, and $850 million in profit, respectively. As his distribution empire grew to include forty-two cities, the price he paid per kilo of powder cocaine dropped from as much as $60,000 to as low as $10,000. ”