Wow, $50 for one mirror 😅
true, not cheap but experience has taught me with stuff like this you really do get what you pay for
the cheap chinese ones ( maybe $30 a pair ) might look the same - this or other designs - but
the hardware that holds the arm to the bars will be rubbish - probably little better than the sort of expanding bolt you put into a brick wall to hold a shelf up
the finish- especially black - won't last, it will flakew off, if its chrome, it'll rust straight away
they'll need adjusting all the time as they won't do up properly
the mirror glass ( if its glass and not plastic) will fall out from time to time
the screws that hold the mirror frame to the arm will be behind the mirror glass ( which kind of makes it handy when the glass falls out, you can tighten those screws up...)
whatever fasteners/bolts they provide to hold it on/together will rust almost immediately
ask me how i know this...............
i have in the past used genuine Stadium bar ends and they were lovely, fitted easy, worked perfectly and stayed unrusty for the whole time i used them
also above the bars is where i've found best to mount them, and outboard of the ends of the grips, doesn't look as good as inboard and under but in that position can't actually see them, so thay satisfy legal requirements but bugg3r all else