I too have doubts about their longevity, but with eight of them it should be a lifetime supply.
Yes, but how many times do you want to do the job over and over again. Buy quality, do it right the first time. Not saying you get more for a higher price, but sometime it just pays to do it right the first time.
I guess it remains to be seen how long they last before worrying about doing the job over and over again. If they never fail then there is no problem; if they do fail I have spares. The number of seconds it takes to change a plate bulb in a factory bumper can be counted on fingers and toes... very easy.