I always sell cheap, the way I see it, it is easy money and I have a fast turn around. I usually end up with several rares per session and they were starting to crowd my stash. If my choice is vendor for ~400 gold, salvage for a few mats I won't use or sell it on the AH for 5-8k, then the choice is easy. I could probably get more for the stuff I find but I'd rather it be gone fast and help someone else out. Also, when selling, always list a buyout price, as others have said in the thread the 2d wait can be brutal and wasteful, give people the option of getting the item immediately.
Yeah, adding in a reasonable buyout seems to be absolutely key to keeping your shit cycling. The worst is sitting on 9 auctions with zero bites and having to wait those two days before you can adjust pricing or sub something else in. Meanwhile, your stash just piles up with more and more crap.