I'm concluding that scopes listed at various sites and within the average homeschooler's price range are pretty competitively priced, but they all have different options so one really does have to concentrate and do some homework before purchasing. I suggest taking notes while perusing different websites and giving oneself plenty of time to figure out what features are truly important. I'm just offering information that I dug up while casually looking around and some random thoughts I have on microscopes after having used a few different kinds. Hopfully it will be of some help to someone.
BTW, my experience is limited to compound microscopes which one will need if wanting to complete highschool biology labs that require slide viewing. You should be able to learn the difference between compound and stereo microscopes by checking out this article at Home Training Tools: http://www.hometrainingtools.com/articles/how-to-select-a-microscope.html
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We purchased a good quality compound microscope (that is very sufficient for highschool level work) from Sonlight a number of years ago. This page lists their microscopes: http://www.sonlight.com/science-microscope.html and this link describes their Ultra microscope in detail and some general information as well: http://www.sonlight.com/microscope.html
What we bought was comparable to the one ultra scope described above (it may have even been an Ultra scope). We paid just under $200.00.
In case you go looking elsewhere, let me recommend a few things that I believe will make using a microscope a much happier experience (the Sonlight microscope has all these features - and I think they've possibly added more since we bought ours):
-An inclined eye piece (otherwise you have to stand over it and bend your back to view anything - or find a table low enough to put it on so you can sit down, which could be tricky).
-A built-in light source (some have a light source that plugs in separately and you then place the bulb & it's socket in a "holder" of sorts. I've found these to be frustrating to try to get in the right spot and hold still). Do NOT buy a microscope (or spend much money on one) that does not have an electric light source. I tried to use one that uses reflected light and I considered it useless for serious microscope viewing.
-A mechanical stage (this allows you to move the slide ever so slightly up & down and left & right with the turn of a couple knobs while viewing the specimen). This will eliminate much frustration and wasted time trying to bring the specimen into the viewing field.
Also, while I did not purchase a carrying case at the time I bought our microscope, I really wish now that I had. It's hard to bite the bullet after all these years for a case, but I really should. Not only will a case protect the microscope from dust, it will make carrying it places much safer (if you ever want to take it to a co-op class or to a friend's to share a lab, you will be thankful for a case. We tote ours around in a cardboard box and every time I do, I wish I had a case. (I wrote that like 4 years ago and I still haven't bought a case. I'm probably hopeless at this point.)
Following are some links for where one can purchase decent microscopes for highschool level work within a reasonable price range (though there are many other sources as well):
http://www.greatscopes.com/ (Great Scopes)
http://www.hometrainingtools.com/ (Home Training/Science Tools)
http://www.smsoptical.com/ (SMS Optical)
http://www.microscopeworld.com/ (Microscope World)
http://microscopeuniverse.com/ (Microscope Universe)
http://www.workshopplus.com/ (Nature's Workshop Plus)
Happy shopping!
