Reddit reviews AmScope T490B-DK Compound Trinocular Microscope, WF10x and WF20x Eyepieces, 40X-2000X Magnification, Brightfield/Darkfield, Halogen Illumination, Abbe Condenser, Double-Layer Mechanical Stage, Sliding Head, High-Resolution Optics
We found 2 Reddit comments about AmScope T490B-DK Compound Trinocular Microscope, WF10x and WF20x Eyepieces, 40X-2000X Magnification, Brightfield/Darkfield, Halogen Illumination, Abbe Condenser, Double-Layer Mechanical Stage, Sliding Head, High-Resolution Optics. Here are the top ones, ranked by their Reddit score.
Trinocular compound microscope provides high magnification for biological use and educational applicationsTrinocular viewing head with vertical camera mount and binocular mount with interchangeable pairs of 10x widefield and 20x widefield eyepieces and Siedentopf binocular head with 55 to 75mm interpupillary adjustment, fixed 30-degree vertical inclination to reduce eye and neck strain, and 360-degree rotation capability to provide a more comprehensive view and enable sharingForward-facing nosepiece with 4x, 10x, 40xS (spring), and 100xS (spring, oil) DIN achromatic precision-ground optical-glass objectives that provide color correction of magnified imagesBrightfield/Darkfield, halogen illumination with rheostat to control light intensity, and 1.25 NA Abbe condenser with iris diaphragm and rack-and-pinion focus control for precise focus, clear examination, and light controlDouble-layer mechanical stage with 1mm stage divisions and stage stop; graduated coarse and fine focus with tension control to prevent stage drift
Amscope and OMAX (owned by the same company) are very big retailers of Chinese microscopes on Amazon. Also Swift.
In the price range you mention, Amscope has been pushing their T490 quite a bit and have lots of attachments for it. Given that you want a new scope from amazon for that price, not a bad bet. The link below includes a darkfield condenser (for getting images with a dark background with the sample lit) and a trinocular head you can use when you want to take pictures or videos.
https://smile.amazon.com/AmScope-T490B-DK-Magnification-Illumination-High-Resolution/dp/B004TP7KDM/
I haven't owned or used it, but it's kind of a safe bet by virtue of being popular and in the right price range. There are plenty of competing scopes in the same price range--mostly the use the same optical system, which is good for the price. By adding or removing features you want, you may end up with different models or brands. There's a pretty competitive market on Amazon.
On the Amscope website there's a live chat you might find useful (they also have a clearance section you might check out). They will give you advice after you tell them what you want.
You can get much better gear on the used market, but you have to deal with broken, dirty, and missing parts and the burden of search/repair/uncertainty is on you.
Soil microbiology was one of the main reasons I bought my scope. Another was yeast in brewing. I'm now amazed at how useful it is for odd week to week things. Here is the one I picked up. It's a bit more than the one you linked but I've been very happy with it. I also purchased the amscope digital camera to go with it and it's just so-so.