Possible magnification range: 10-100x (dependent on objective lenses)
discarded photo enlarger
8 X 21 mm binocular
some pieces of scrap wood
Optional: some discarded camera lenses, piece of aluminum sheet.
Costs: 15 - 20 E / $
I built the microscope on this picture some years ago, but made another one for this instructable. So I did not spend much time to put a nice finish on parts.
Step 1: The stand
Take the mechanism part of the enlarger off the base. The lower part, below the film holder will become the base of the microscope. Take it apart from the light source and condenser.
The rest of the enlarger is no longer needed. It might serve as a stand for copying documents.