I was searching for a microscope and I saw some with prices of over 10.000$. However I need to buy one that can actually show me the cells of a culture I am growing at home, and I really need to know how much "zoom" I need to see them.
You can see a few like paramecium with good bare eyes. A 10 magnification loup will reveal more. For general amateur use a stand held binocular ( not distance type binoculars) is very versatile, and common, traditionally 7 X to 40 x magnification. Any more magnification will require special lights ,sample preparation , etc.