Afghani farmers began growing saffron to replace opium as a cash crop, but now the spice is suffering falling prices. The scam John Dvorak uncovered is that many spice merchants claim the saffron is from Iran, but it's really grown in Afghanistan and resold.
While Adam was plotting a trip to Syria (NA #418). John encouraged him to pick up some spices while he was there. He recommended the plentiful saffron along with some cheap caviar which is available in large tins.