That maybe true but many amateurs pay premium prices for certain brands with the expectation they are getting exceptional quality optics. Then they go years believing the image they are viewing is as good as it gets. A little bit of education on how to test optics and now you know what your getting vs assuming. In this thread we have seen photographic proof of both a not so great lens and ones that is.
There is another thread going on right now about the whereabouts of 6" Unitron. It was mentioned that one in good condition might sell for $50,000. I'm sure a buyer won't be too pleased to find out after a purchase when the optics were tested that they had issues when the talk in the thread, most believe it would the 'Holy Grail' of telescopes to view with.
I guess everyone on this list has learned to test their optics in one way or another and everyone has experienced that frustrating moment when you get a substandard optic or the exhilaration of getting a top notch one. We left our assumptions behind years ago but it was fun seeing through that first 60mm refractor thinking that it was great even though the lenses were at most fair.
The $50,000 6" Unitron is a fascinating thread .I hope that it is found and the optics are great.