AstroAds
   Buy and sell equipment and accessories.
   http://astroads.com

AstroMart
   Everything for the astronomer including news, classifieds, auctions, articles, forums, and a calendar.
   http://www.astromart.com/

Astronomy Mall
   The sale of hobby related equipment and accessories listed for free.
   http://astronomy-mall.com/

Astronomy Pinboard
   Accessories, software, observatories, binoculars, telescopes, components, photo equipment, and miscellaneous items.
   http://pinboard.astroinfo.org/

Canada-wide Astronomy Buy and Sell
   Contains new and used telescopes and accessories.
   http://www.astrobuysell.com/

Chicagoland Astro-Ads
   A free service to amateur astronomers in the greater Chicago, Illinois area to post astronomy classified ads, and shop for used astronomy equipment.
   http://www.stargazing.net/naa/ads.htm

Cloudy Nights Classifieds
   Classified listings of used telescopes, accessories and observatories for sale.
   http://www.cloudynights.com/classifieds/

ScopeTrader
   Reflectors, refractors, mounts, cameras, scope building, eyepieces, and observatories.
   http://scopetrader.com/?l=/Classifieds/allview.asp