First thing to keep in mind is that microscope kits are more expensive than most of the other biology boxes. Not only that, but they are also breakable. In fact, there are more than a few things that are breakable in a microscope biology kit like the lens of the microscope itself, the slides, and test tubes. While the petri dishes are made of plastics, they too are fragile. A microscope kit, for all these reasons, is more suitable for kids that are eight years old or above. But it is the kids older than ten years that will be able to make the most use out of it.