I don't think you get how cheap rokkits can be.
Yes, but there are no relatively
cheap accurate and guided rockets with a range of more than 1-3km. (Stinger and Russian counterparts)
Katyusha's are cheap, but unguided. Anything that can actually be fire and forget from punched in grid coordinates is going to be very pricey as compared to hexacopter or any of these other GPS "hobby" UAV's.
And another way to maximize target damage with minimum explosives payload would be a conical self-forging copper disk warhead.
Better for vehicles and anti-material work, than anti-personnel. OTOH if the personnel you're after are inside the material or vehicles...