Why isn't better quality used gear being made available?

It all comes down to how badly you want something specific, and what sort of energy you're willing to expend.

Some years ago, I wanted to buy a particular used Norwegian machine
It took just over a year with 3 search bots combing the net to find one, fortunately in great shape at a reasonable price at a Boston Habitat.

I consider myself lucky; it was nearly pristine for something 2+ decades old, due to apparent unuse. 🤷‍♂️

'Specific audio' may require the same sort of search, and the wherewithal to recognize and respond quickly...;)

@tattooedtrackman ....*L* The wait simply requires patience, virtuous or not.
The part that gets to you is seeing an auction that I missed out on, held a month prior to beginning my search....  There were 3 of them; 2 complete, one missing some parts.  Never found out who/where/how much on any...😖

Given the time from that to when I saw and bought, I may have one of them by  no default of my own....but I kept seeing the same auction post throughout my search.

...and That, my friend, is annoying.  Couldn't tell the bots to ignore certain things, they'd just dutifully report them....over 'n over 'n over 'n....*sheesh*L*

Audio-wise...or perhaps not...
If I was in the state of 'upgrade fever' (and the means to Go There...) (No...), I'd likely Go Here....

....a MRA 16.75+ would be interesting to play about with....

....but would likely trigger a 'cascade event' in expanding the means to 'feed it', since I'm at 12 channels already....and already 'living in The Matrix.....*LOL*