Silk Road, the online black market, offers prescription opioids, such as oxycodone and morphine, at almost exactly the same price as what’s found on the street, according to research recently published in the Journal of Medical Internet Research.

Finding reliable data about black market drugs has always been difficult. This research sheds some light on Silk Road’s viability and shows that the crowd can be a reliable way to answer the age old question: Just how much should I be paying for a single 30 milligram Adderall pill? (Answer: $5.)

“Street prices of diverted prescription opioids can provide an indicator of drug availability, demand, and abuse potential,” the authors wrote.

The researchers solicitied information from three primary sources in early 2012: the crowdsourcing site StreetRx.com (which recorded 954 responses); law enforcement officers in the Researched Abuse, Diversion, and Addiction-Related Surveillance (RADARS) System (737 reports), a prescription drug abuse and diversion system “that collects timely product-and geographically-specific data”; and actual transaction prices on Silk Road (147 reports), which is accessible only through encrypted Web browswer Tor. The researchers found the prices to be “nearly identical” from all three sources.

The black market, the crowd, and the cops were also able to “accurately predict the relative pharmacologic potency of opioid molecules,” writes Chris Menone, one of the paper’s authors.

Photo by Be.Futureproof/Flickr