I think most people who play the Auction House in Diablo 3 are focused on high end items. Apparently, a lot of botting is hurting the economy on top of that and Blizzard has done little to handle that issue. One thing I have noticed that I’m not certain is a direct correlation to the rise of botting in the game is that items with ilvl 43-59 (and arguably 60-61) do very poorly in the Auction House. I believe this is occurring because of the level reduction items in the game.
Most level reduction items start from around level 42 and go up to, of course, 59. For gaining the level reduction stat though, you will receive items that can be used by level 60 characters. Obviously, that provides a huge advantage while leveling up (and I do think this is intentional). In World of Warcraft terms, these items are similar to Bind-on-Account leveling items such as weapons and the experience gaining armor.
Naturally, if you manage to secure enough funding, then these items are eventually the way to go as you finish off your last few levels before hitting 60 (after all, who doesn’t want to power through the game and be in Inferno mode?) Items like weapons are pretty much worthless as the DPS is too insignificant compared to something that can potentially do 1k+ DPS and possibly get you started in the intro for Inferno mode.
That said, I do think there are a few items that can sell within this ilvl range. Namely, follower items, rings and amulets. I haven’t seen thus far any items that might be reduced in this regard, but I’d have to double check. So if you need to use the Auction House to make some spare change, I would suggest selling these. Otherwise, you’re better off just vendering any rares or salvaging them for parts.