Depending on a shopper's location, Craigslist.org lists a variety of used paint sprayers and accessories. EBay.com and Amazon.com also list used paint sprayers, although Amazon.com's used listings are rather limited. Another option is CJ Spray, a company that reconditions and sells returned Graco paint sprayers.
A search on Craigslist.org in several cities results in numerous listings of paint sprayers and accessories, as of March 2015. For example, The Craigslist.org's Minneapolis site has Wagner, Milwaukee, Titan and Graco airless paint sprayers for sale, with a range of models designed for professional or household use.
EBay.com offers new, used and refurbished paint sprayers as well, with some listings offering free shipping. Amazon.com offers mainly new paint sprayers, though most of the models for sale have at least one used listing for a slight discount. Again, Graco, Wagner and Titan brand sprayers are the most common.
Another option is to go through a company such as CJ Spray. CJ Spray manages Graco's factory reconditioning program, offering mostly like new and slightly used Graco sprayers. The company details the specifications for its ratings system and describes the reconditioning process on its website. CJ Spray generally offers a 90-day warranty on used sprayers. They also offer phone support if the new owner has problems or questions.