Good point—
A good quality and not terribly expensive pleated filter will work just dandy–
as long as it is changed regularly. Once the filter plugs up—it will bleed through. And bleeding through means all that crap goes on the evaporator.
Dirty evaporator means poor air flow, means iced evaporator, means no cooling and a possibly liquid slugged compressor (==compressor dies). And who wants that to happen? Certainly not your technician.
Nothing trickier to access, messier, dirtier, cut your fingers and arms all to hell is there than to clean that evaporator once it gets dirty.
So use a cheap filter, preferably pleated, if you want to--------but for Gawd’s sake CHANGE IT REGULARLY.