When Japanese newspapers or TV news report about confiscations of cannabis they often use police estimates of how much the hemp drugs would have been worth at "street prices". These reports usually suggest a price of ¥5,000 per gram (US$50 at ¥100/$) for marijuana or ¥6,000-8,000 (US$60-80 at ¥100/$) per gram for hashish. These estimates use exaggerated prices as the police tries to make their catches look more impressive, as they do in all countries.
http://www.youtube.com/watch?v=NlLBb3j6qRQ