I recently picked this guy up at university surplus. I don't think it saw much classroom use, since the optics are in great shape and everything works.
150usd plus shipping
This is a classic stereo scope in the older VM series from Olympus. It has a turret mag changer, meaning you rotate the nose to get two different magnification settings, 1x and 4x. With the included 10x olympus eyepieces and 1.5x auxiliary you can get up to 60x magnification, with quite pleasing results. This one comes with a 1.5x auxiliary objective attached. Turret objectives aren't as sophisticated as a zoom system but they give a very bright crisp image. It's mounted on an illuminated stand that switches between brightfield, reflected light or both with the switch of a lever.
There are two minor issues: first, one of the focus knobs is cracked, though this does not affect function. Second, at some point the bulb was left on too long and part of the plastic under the scope partially melted, and the hole which the battery compartment clipped in to widened enough that it didn't want to stay in place. I added a layer of JB weld to make the hole smaller again and it clips in fine.
I got my hands on a few of these, all in good shape, so let me know if you're interested.