If you're finding and picking up shit gear. I'm pulling in 500m+ a week with a single bot.
If you are doing that much gold allowing the market to set the price for you, good for you! I was pulling 1,5b daily on average for the last month, yet the recent news have shattered my sales to half of that. That's with 10 bots, and devoting 2 hours daily to deal with sales and refilling the auction.
In my experience, when I gave a chance to open market (expecting what you said, that several people would want the item and it could get overpayed for) all I got was a huge dissapointment. Items worth between 50 and 200 m went sold for 13m or less. Not one or two of them, dozens of them....won't really do that again, yet from time to time I check the AH filtering by fewest time left to find bargains.
The great issue with that is, most people playing don't really want use the auction house (as proven by the recent news) and when they use it, they want an upgrade instantly. The bidding market is mostly composed of auctioners who really know the price most items will sell for. If you are paid 200m for an item, chances are the item will be selling again on a 3x-5x value on the Buyout market.
But back to the OP, you really need to use loot rules unless you wanna spend huge amounts of time clearing your stock. Gnillers (too hard for my taste, yet I understand someone with 30+ bots really needs them) or Darkfriend's hard Rules (My pick, I change them according to the market, but they work great for picking everything worth 2+m, and some utter crap you'll have to get rid of)
And if you devote some time to check the ah in order to set a price for your loot, in no time you'll get to know the market, and you would be able to price an item properly!