So depending on the monkey the robot may be cheaper.
Another cost farmers will likely look at is the cost of a monkey handler, which are widespread vs the cost of a specialised employee who can operate a robot. Unfortunately, the monkey handler is likely cheaper.
As far as i know training this monkeys takes time, the robots will do the job right away if you put this in the long term the robots is cheaper than keep a monkey. But of course they should make it simple in the way that a non specialized employee can operate the bot without any problem.
Another cost farmers will likely look at is the cost of a monkey handler, which are widespread vs the cost of a specialised employee who can operate a robot. Unfortunately, the monkey handler is likely cheaper.