The 'farm gate' price for Afghan opium WAS around $120/Kg and has now increased to a truly HUGE $400/Kg since the Taliban 'banned' growing it. Mexican heroin WAS $315-$415/Kg so how anyone can arrive at $500 million by any legitimate calculation is beyond me.
But please note - the price of opium is very low indeed. The street price of heroin has almost nothing to do with the price of opium. When you consider that a few acres are grown in the UK and The Czech Republic actually produces quite a lot while a huge amount is grown in Tasmania showing that the poppy does not require the arid, semi-desert environment people imagine.
There is disclosed an improved poppy straw of a stably reproducing Papaver somniferum for the extraction of thebaine and/or oripavine, the threshed straw having thebaine and oripavine constituting about 50% by weight or greater of the alkaloid combination consisting of morphine, codeine...
patents.google.com
Now the above patent is for what is referred to as the 'NORMAN strain', the brilliant acronym simply means No Morphine. What's interesting is the patent also notes the simplicity of converting thebaine to oxycodone and oripavine to oxymorphone. Actually, reflux in HBr will convert oxycodone to oxymorphone in about 87% yield so already one could reduce the amount of poppies needed to sustain the market.
I haven't tried oxymorphone but I've never read a report that didn't regard it as the most euphoric opioid available and it's x5 more potent than H. So in a low-tech manner one can, after the first harvest, have a highly desirable product.
BUT any medicinal chemist will point out that thebaine and oripavine are also valuable precursors. A little more sophisticated chemistry (Diels-Alder reaction) yields 6,14-Endoethenotetrahydrooripavine which isn't exactly a well known drug but is some x400 M in potency and is (from the two reports I have) subjectively almost identical to oxymorphone. Some more chemistry and one can arrive at M320, which is some x9200 M. Now that one I have no reprts on.
In essence, to anyone collecting long-term surveillance would see a legal enterprise; failing. By the time oxymorphine is hitting the streets the grower has switched to 6,14-Endoethenotetrahydrooripavine requiring only 10% the area of poppy production and by the time that hits the street M320 is the product and yet poppy production would, again, have dropped by 90%.
From that point their are actually a LOT of homologues possible.