All out, the biggest brand out there for mosquito repellant machines, is really not that effective.
Although it is simple to use, and the refills are easily replaceable but it’s real job, which is to keep mosquitoes out isn’t really perfomed very well.
Also, what it emits is poisnous to us humans as well, so people should not be staying in immediate contact with the machine in use
Cost of the machine isn’t really a matter.
More often than not, it rather feels as if the mosquitoes come in more quantity when the machine is turned so I would not recommend using it.