In the 80's, Jamaicans couldn't turn in Jamaican Dollars and get US Currency in exchange so US Dollars were a hot commodity. People would take US Dollars to Miami and purchase auto parts to bring back to Jamaica to sell thus making a whole heap of money in the process. Today US Dollars are sought to hoard as a hedge against Inflation and constant devaluation of the Jamaican Currency.
It really makes little sense to use the Black Market to exchange money these days as the small amount of return possible is well outweighed by the possibility of getting counterfeit currency or ripped off during the transaction.
Peace and Guidance