Define cheap and multiply by thousands. Ukrainian front line drones stopped being DJIs years ago.

They're now much closer to $3000 USD+ at the low end for an ISR vehicle. $8000+ for the more capable FPV kamikazes is the estimate for Russian models.

Which is comparable to a 155mm artillery shell. But with a lot less payload.

There's already literally millions of drones being produced and used per year in that conflict - and they've made a big impact, but the stability of the frontline also reveals that the impact of "swarms" is hardly overpowering (the obsession with them is also weird - if you had thousands of assets in the air, the last thing you'd do is put them all close together).

> overpowering

As Iran shows, you don't need overpowering. You need to hit the enemy where it hurts them, like strategic infrastructure.

> "swarms" ... (the obsession with them is also weird - if you had thousands of assets in the air, the last thing you'd do is put them all close together)

On the contrary, a swarm allows you to overwhelm the enemy air defences, which allows you to hit targets, including those same air defences, without having to disable them first. Cf. Iran destroying a THAAD radar.