For each drone you have one expensive pilot, and maintenance costs also. Plus you have to factor in that the range is extremely limited, the speed is 1/15th of a chopper. Taking those factors into account the chopper is cheap, considering what you can do with it compared to a drone. The cheap toy drones that can stay up for 20min max, are like 90K. Pretty limited use cases, although they do open up new capabilities . Comparing them to a heli and saying they will save cost is not the right argument. It's like saying the city should replace their garbage trucks with bikes and trailers, cause you'll save so much money on maintenance.