Try to find used but in good condition Olympus or Zeiss ones. I've not used the Nikons before so i can't comment.
It might be a point of interest to note that before Olympus became a 'camera' company, they actually specialised in medical and scientific instruments, os so I was told.
E-bay and any forum where medical/scientific folks hang out should be a good starting point for shopping. But do some research first so that you at least know what you're getting into.
at least for microscopes, olympus, Nikon, Carl Zeiss and Leica.
Olympus and Carl Zeiss optics for advanced microscopes like the ones i use are EXTREMELY SHARP and the colour rendering is fantastic
..... while Leica and nikon are definitely good too.
i have a super OLD Leitz Weztlar HUGE microscope but without the optics that is inside the locker as a gift for clearing out some godzillion years ago's lab .............
now trying to source for parts to the optics to see if i can make it a functional (not decent i'm sure) ornament to my house when i return
Yo bro, seriously, take some time to go through the ebay listings and start contacting multiple sellers. You'll be surprised at the gems you can find there, but I'm afraid that there's no siamnzing the legwork.