Microscopes are instruments used to increase the magnification and ability to view things that are much to small to be seen with the unaided eye. The earliest microscopes were optical microscopes, which relied on a set of lenses used to refract light. With the advancement and innovation of electricity and technology, reflecting microscopes (with mirrors) were used. The shorter the wavelength, the better the resolution, so ultraviolet microscopes were invented to see things using ultraviolet radiation, which is higher in the electromagnetic spectrum than visual light. Electron micrscopes are used to see the tiniest of the tiny, bombarding specimen with streams of tiny electrons, and recording the reflections of such through visual monitors.
"Typical magnification is up to 1500X, with a theoretical resolution limit of around 200 nanometers," is what one would expect for most reasonable optical microscopes manufactured today. Pricing for such a unit varies from company to company, but would range somewhere around $150 to $400, depending on quality and options.