The used market is always full of lenses, and given how well many photographers take care of their gear, you can often save a fair bit of money and still get a quality lens by purchasing preowned. There are a few things you should check before you agree to buy that lens you are eyeing, though, and this quick and helpful video tutorial will take you through them all to make sure you are not wasting your money.
Coming to you from Lensrentals, this great video tutorial will show you nine things you should check before you purchase a used lens. Buying used can be a fantastic way to save significant amounts of money, and it also allows you to try out older or more esoteric gear that you might not be able to find new. At least half of my current gear was purchased used, and it has saved me literally thousands of dollars, plus I really enjoy trading and trying out vintage lenses with unique bokeh or other interesting characteristics. As long as you do your homework and purchase from a reputable seller, you can often get a great deal. Check out the video above for the full rundown.
One more thing to check: (10) Does the lens focus to infinity? I bought a Nikon 70-300 mm zoom lens for a bargain price on a well-known auction site that worked quite satisfactorily --- except it could only focus out a few hundred feet, but not out to infinity. It probably just needs an adjustment, but I found an identical perfectly working replacement (also used) lens in the mean time.