Best microscope-camera setup for a classroom

Define reasonably priced. You could make do with a digital camera and a good pair of binoculars. You could buy a cheapie USB camera. You could buy a fairly decent introductory biological microscope (400x will let you see a bacterium, good enough for my college bacteriology class) and hook a webcam or digital camera up to it.

I am an archaeology graduate student and I've been using a Dino-Lite digital microscope to take pictures of artifacts and store them on my computer. I've been using the 313T which I think has been replaced by the 411/413, but the microscopes come with a variety of features depending on your needs. The software is also quite good, available for mac and PC, and you can take photos and video and store them on your computer to show in class later. For my purposes, it is helpful that you can annotate your images as you take them (i.e. with a catalog number) and there are also options to measure samples on the screen, although I've never used it. If your class has a projector set-up you can use the microscope live on your computer and project the results on a screen. I ordered mine from BigC (you will have to google this because my answers keep getting flagged as SPAM with the URL included).

You can get the Dino-Lite microscopes at The Microscope Store. You should give them a call and ask their phone reps, they're really friendly and helpful without pressuring you.