I have read $20K per Shahed Drone, but no matter.....generally systems fire 3 Patriot missiles or missiles from a THAAD at each drone, so the economics work much better for Iran. Using those $20-30K Shahed Drones, Iran destroyed a $1.2 billion THAAD system in Qatar and another one in Abu Dhabi. As for dirty bombs, fortunately the best enrichment Iran has ever achieved is maybe 60%, so actual nukes are still a long way away. Of course, before Trump tossed the JCPOA, Iran only had medical grade enrichment, and they ceased trying to go higher. Trump is like the arsonist who starts a fire, and then demands applause if he puts the fire out. Of course, the fire Trump set he cannot put out, absent either hundreds of thousands of boots on the ground, or else genocide with nukes. I think Trump will choose genocide, as that would definitely get him in the history books...and isn't that what it's all about.