If it's like the sahed drone then it costs about $30k, has the range of a "medium-range" ballistic missile (which cost millions of dollars), but moves at ~115mph vs supersonic. They also have more limited payload.
So the general principle is that you can produce them quick enough that you can deploy enough to overwhelm your enemies defenses. They also use satellite and interial navigation so can be fairly accurate.
If you haven't seen it before this is a highlights reel of bandit Keith in a spoof dubbing from yugioh abridged https://www.youtube.com/watch?v=OBbodtKylqs
Edit: Shorter clip of the best scene - https://m.youtube.com/watch?v=ji2UoU0rUX0