I just started using AAdv today and it is much better than classic in many ways. The one problem I have though is that if I have an item and I am not at the auction house, I can't tell if the item has competition.
For instance, say I just scanned AH, and I go to my bank to see if I should withdraw an item to put it up on ah. In classic it would tell me if there was "no competition" "can't meet lowest price" etc. In AAdv I can't seem to find an equivalent.
Also, in the appraiser tab, am I correct to say that you should only post an item when there are no blue or green auctions already up. (i.e. 11/2/3/6 in different colors) In classic it tells u off the bat if you can or can't sell it, while in AAdv it makes you decide.
you should have the 11/2/3/6 in the tooltip as well
As for your question on when you should post, that's up to you, your style, your PriceLevel settings (which set what the colors mean), and the particular type of item. Maybe the competition is so low that you want to ignore it, because it will most likely get bought up very quickly, even if it's not worth it to you to buy it out yourself.
I'm sorry but I cant seem to find the part of the tooltip that says the results of the previous scan. There is nothing that says that there is no competition, or that there are many auctions that are underpriced.