Audible Difference
Demo and pre-owned audio equipment.
http://www.highendaudio.com/demos.htm

Ahead Stereo
New and used stereos, audio, video and electronic equipment.
http://www.aheadstereo.com

Recycled Audio
Used audio gear.
http://www.recycledaudio.com/stuff.html

The Sound Well
This Berkeley, California store Specializes in reconditioned hi-fi equipment.
http://www.thesoundwell.com

Goodwin's High End
Used, demo, and closeout equipment from New England's largest all-high-end audio and home theater retailer.
http://www.goodwinshighend.com/used.htm

Vintage Hi-Fi
Used classic hi-fi equipment and parts.
http://www.vintagehi-fi.co.uk/

Audio Exchange
Used audio and video equipment.
http://www.fredsoundofmusic.com/audio_exchange.html

Gabriel Sound
Used audio equipment sales including vintage, collectable, used and demo units.
http://gabrielsound.com/shopsite_sc/store/html/page10.html

Signature Sound
A variety of equipment including amps, cables, turntables and stands. Also provides information about its new equipment sales through its Liverpool, New York store.
http://www.sigsound.com/

Galen Carol Audio
Used and demo audio equipment.
http://www.gcaudio.com/

HiFi Audio Sound Parts Materials
Selling parts stock, service manuals, unclaimed equipment, cadavers.
http://myweb.ecomplanet.com/HIFI2650/

Audiojumble
The annual UK event dedicated solely to the buying and selling of second-hand and vintage hi-fi.
http://www.audiojumble.co.uk

classicaudio.com
High fidelity art from the 1970's, Service and Parts.
http://www.classicaudio.com

Audio-Video Logic
Used and demo audio and video components available USA nationwide, and new equipment available in the Des Moines area.
http://www.audio-logic.com/

VinylConnections
Vintage audio equipment such as turntable, loudspeakers and recording.
http://www.vinylconnections.co.uk/4sale1.htm

AllegroSound
Buy, sell and trade vintage and high-end audio.
http://www.AllegroSound.com

ProAux.com
Free online auctions specializing in pro audio gear for recording studio, live concert sound, and Dj equipment.
http://www.proaux.com