Use for Counting Yeast?

I’m looking at standard microscopes but would rather build this.
I would need 400X and the ability to mount a Neubauer Hemocytometer
Like this

Why do you need 400x? (which is starting to get expensive) … couldn’t you do something software with guesstimating the color intensity or perhaps a plugin from uManager (eg Intelligent Acquisition) rather than risking eye strain? (or pass to someone on mechanical turk)

I missed this post when it first came up. By 400x, would that mean a 40x objective and 10x eyepieces? The Openflexure microscope is quite capable of using 40x or 100x objectives, and field of view of the camera is more than with 10x eyepieces. It images blood well.
It looks as though those Haemocytometer slides are designed for an upright microscope. Can they be turned over for use with an inverted design like the Openflexure microscope?

Also spotted this bioelectronic gizmo