According to the United Nations Office on Drugs and Crime:

In the United States in 2015 (the most recent year for which data are available), the retail price of black tar heroin ranged from $20 to $300 per gram; the retail price of South American heroin ranged from $25 to $400 per gram; and the retail price of southwest Asian heroin ranged from $120 to $300 per gram.

In Canada in 2014 (the most recent year for which data are available), the retail price of opium ranged from $43 to $55.90 per gram; and the retail price of heroin ranged from $154.80 to $300.90 per gram.