Telescopes can be extremely expensive, especially the larger ones that are still suitable for home use and amateurs but are many orders of magnitude more powerful than other, smaller telescopes. Telescopes can cost several hundreds of dollars on the cheap end, and several thousand dollars on the more expensive end. The more powerful and precise the instrument, the more it will cost. That’s just simple economics, especially since the more precise and powerful instruments will have finer pieces in the machinery. If you really want or need a powerful telescope, there are ways to get one without completely breaking yourself over it. You don’t need to destroy your budget in order to get a powerful telescope. So if you are an amateur astronomer, a full-time scientist, a science teacher, or just somebody looking for a gift for a special somebody, you might want to look into the used telescopes market.
Used models are generally pretty good because telescopes don’t get a lot of wear and tear. If they are properly stored and properly cared for, the worse that you’re going to be looking at is a few scratches and dents, and maybe the need to replace the eyepiece—which also isn’t very expensive. Some stores that sell telescopes also sell used and refurbished telescopes, especially the suppliers and distributors who sell mainly from their webstore and their catalogues. There are other places to find them, including the classified section of the newspaper, and online communities that are dedicated to the discussion and education of amateur star gazers. Most will have some sort of market section where used instruments can be sold or bartered.
A Terrestrial telescope uses multiple lenses to invert the image making the image appear to be erect to the beholder.
Ultraviolet telescopes view the ultraviolet spectrum dynamics that take effect outside of our world.