In a perfect world, yes. In truth, some may not back off.
Auctions can be cutthroat, and are open to all bidders, friends or not. Personally, if a member is bidding and I know it, I will not bid unless that member says the auction is out of his price range, but is still in mine.
In addition, we all know that some have deeper pockets than others, and might have a greater interest in the item at a higher price, especially if the item is rare or is just the piece to fill a collection or set.
I still think we are watching out for each other by noting auctions, and letting each other know our interests and limits.