Yes, I can understand why commercial and research labs buy the new microscopes for tens of thousands plus hundreds for electron microscopes and got rid of their old ones. Better for us hobbyists. I was at the Medical College of Virginia 40 years ago so am perfectly happy using the older scopes since I learned histology, pathology and microbiology with them anyway. Student scopes at that, not the very nice research ones that you can buy so cheaply today. I like watching ibiology on YouTube which has lots of scientists giving lectures about what they learned in their last , sometimes, twenty years of research. They often put fluorescent markers on what they studying and show timelaspse microscopic videos of those things. I did see microscope dealers selling the reconditioned microscope that I bought on eBay for 80 bucks for one thousand instead. Just have to recondition them yourself.
That's what I have been doing over some period of time.
Now, my Leitz Dialux 20 has been reconditioned with he following objectives:
Leitz PL 2,5x/0,08
Leitz Pl Fl 4x/0,14
Leitz PL APO 6,3x/0,20
Leitz PL FL 10x 0,30
Leitz APO 12,5x/0,30
Leitz EF L 32x/0,40
and there is still a gap between 12.5x and 32x.
The eyepieces range from 10x up to 25x, all of the are Leitz Periplans.