Your drone needs to be cheaper than what you're killing, so if your target profile is 50k+ USD and up, a $10000 even is fine (not that it would need to be even 10k).
Your oversimplification bakes in too many assumptions.
The relative financial cost to the enemy is almost irrelevant if they are much wealthier than you are.
What matters most is the intangible military value of the item.
In too many situations people think simplistically about dollars, when what matters is invisible or intangible values. The hyperfocus on money is especially egregious among people that don't have much.
That's obviously not the only metric. The cheaper the drones are, and the less resources they need the more of them you can produce as a result. This is why cheaper weapons that can be produced at scale tend to be most effective.
The relative financial cost to the enemy is almost irrelevant if they are much wealthier than you are.
What matters most is the intangible military value of the item.
In too many situations people think simplistically about dollars, when what matters is invisible or intangible values. The hyperfocus on money is especially egregious among people that don't have much.