Time Magazine has a report on the illicit trade in caviar:

The illegal trade ranges from private individuals flogging jars of caviar at open-air market stalls to well-organized smuggling operations, with paid couriers picking up pre-packed black market roe for delivery to specified customers.

The trade in illegal fishing is estimated to be valued between $4 to $5 billion.

More prices and figures on the black market trade in caviar is available at our Illegal Fishing page.