https://www.agairupdate.com/how-much-does-it-cost/
An acre of cash crop is has gross value of $500-700.
https://farmdocdaily.illinois.edu/2018/08/corn-soybean-budge...
Targeted application by drone makes it a) actually work at all under stricter regulations and b) can be placed only on the areas that need it, so it actually is cost competitive with blanket application despite being more expensive per acre.
That said, in ten years this will probably be all drones. The ability to do precision dosing, safely fly a few feet above the target, lower noise, lower capital investment, no need for commercial pilot, little to no overspray, high automation potential, simultaneous high resolution monitoring, etc etc etc.
Big limitation now are the meager payloads and flight times. Drone delivery is going to open up the market for manufacturers to start pumping out drones that meet that demand and it’s going to be mothballs for the old guard in quite a few places.
Hopefully companies like Air Tractor get on board and adapt their product lines, they have way too much valuable experience.