If defense systems have to shoot three, four, or five Patriot interceptors to knock down one drone, the cost becomes 15, 20, or $30 million per $20,000 drone.

The drones that came over in the first four weeks, those waves every morning were basically carbon fiber wings with lawnmower engines on them and and very inexpensive to make about $35,000.

Patriot missile systems, costing a million dollars per missile, are experiencing "leakage" as cheap Iranian drones (costing $20,000-$50,000) are getting through.

Iran is producing drones for about $30,000 a piece.

Each Shahed drone costs between 20 and 50 grand to manufacture, built with off-the-shelf commercial electronics.