$600 to $1,000
In this price range you get to some seriously capable microscopes. The objectives are at least semi-PLAN if not PLAN apochromatic. Trinocular heads, ergonomic controls, upgrades to phase contrast and polarized light kits, photographic attachments, and Kohler illumination make this class ideal for photomicrography.
Series A Trinocular $900 http://www.microscope-depot.com/seriesAtrinoc.asp