Microscopes can be extremely expensive. High-end versions of electron microscopes that offer extremely high magnification and extremely precise instruments can run into the tens of thousands of dollars.
Anyone who wants to look at a specimen or material under a microscope most likely will have to bring that specimen into the lab to do so. High-end electron microscopes need to be hooked up to a power source to operate and are far too sensitive to be utilized outdoors, which means they must be used in a stable indoor environment.
Microscopes are incredibly precise, fine-tuned pieces of equipment, relying on delicate lenses and lights. As a result, most types of microscopes are fairly fragile pieces of equipment. One errant move could knock a microscope off a table, and it is unlikely the device would survive such a fall in working order.
Microscopes generally allow users to examine materials placed between two glass slides and put between the microscope's light source and lens. However, many types of material do not readily fit between those slides, so extensive preparation of materials is likely necessary. Cutting the material into slices thin enough to fit between the slides could require the purchase of additional equipment, and the process could be time-consuming. Furthermore, users of electron microscopes typically need special training to use the microscopes correctly, which can be an additional costly and time-consuming effort.