> Then two drones approach from opposite sides at 200 MPH.

A drone that can go 300 km/h is way more than 100 $, you are in the thousands of dollar range at that point. Turret wins if it blows up one.

Also, it could probably blow up more than one since at 300 km/h you would get 0.5 seconds to respond and I was arguing 0.1 seconds per target anywhere in a full 360. 0.25 seconds for anywhere on a full 360 would be enough for 2 and that is within human capability.

> you send in a cruise missile to clear it out

Cool, you sent in a hundred thousand dollar cruise missile to blow up a thousand dollar turret. Turret wins. Also you can put wheels on the turret, so it might not even be there.

Now you are probably going to argue about a drone that goes 1000 km/h at which point what you have is a cruise missile which costs tens to hundreds of thousands of dollars. At that point the entire argument about drones being too cheap to cost-effectively stop is moot.

Or you might argue that the drones just go high. 50 m is a ludicrously low flight ceiling. But then your drone can not explode on contact. You could use a drone that drops explosives, but that still requires flying over the target. High flying drones are easier to detect, and you could counter that with flying shotgun drones or turret mounted machine guns which have ranges in the hundreds to thousands of meters and would still only cost a few dollars of ammo per kill.

My main point is that bullets can easily disable a cheap drone and are much cheaper than a cheap drone. You just need a cost-effective way of deploying mass bullets against mass drones. Logical answers are ground deployments around targets or drones with bullets that cost-effectively shoot down drones without bullets.

You will then likely get into a arms race of fighter drones to protect your bomber drones. And scale up your drones until they are not easily bullet-destroyable. But then your drone costs have likely increased to the point where anti-air cannons shooting 100 $ explosive shells are cost-effective. And so on and so forth.

> Cool, you sent in a hundred thousand dollar cruise missile to blow up a thousand dollar turret. Turret wins.

Nope. The calculus is not about individual components, but about overall cost of the entire system and all of its associated support. What was the material, labor, and opportunity cost to install the turret? What was it protecting (which is now presumably destroyed by drones, or captured by the enemy)? You're also still assuming that you're facing off against guerillas fighting an asymmetrical war on a shoestring budget, but that's not the case. Whatever force you're fighting can be trivially bankrolled by a peer power who is happy to bankroll them to make you bleed to death. China will be happy to build plenty of cruise missiles, and plenty more drones.