How can I find good quality discounted audio gear?
Nothing beats word of mouth. Ask other producers, technicians, and musicians in your area who you talk with (I presume you do some networking). Everyone likes a deal; see what your contacts do for theirs.

Here are a few approaches that I've had luck with:


Check classifieds, both on paper and online classifieds such as Craigslist. Look for organizations that are going out of business or upgrading their stock. Check the garage sale section, too. People occasionally clean out their home studios. Does your area have an auction site? I bought a nice synthesizer once from a site like that, through a local college that was upgrading their music program's equipment.
Look to see if there is a regular swap meet or flea market nearby. In my area, there is an audio swap meet every six months, plus a weekly general market. I've found decent used gear at both of these, and generally you can try it out.
Finally, search for pawn shops. Most cities have at least a few, and most of the ones I've seen tend to have a bit of musical equipment. 
Look for "deal of the day" sites such as goingtoday.com or woot.com or Musicansfriend's Stupid Deal of the Day. You will probably have to wait a while before something you need shows up, but when it does, it's usually under retail price, and usually refurbished.


Very little of this applies specifically to audio equipment - variations on these basic ideas could work for finding TVs, cars, computers, whatever.