I didn't understood what you've meant...
I'll try and give an example (that I think I've already gave...).
Two users sets and auto-bid for an auction that will start at 00:00.
They will set their bids to 5K and not more than 100K (the same for both).
Let's say that each bid should be with 5K from the previous bid, just for convenient.
The auction starts.
At 00:00 the system calculates who should get the last bid between the auto-biders.
Let's say that it is user-A, and this means that the current bid is 95K.
Now the bid-war is free to all.
In case a user put it's bid before 00:01:30, then the auto-bid is over, and the auction is only against the online bidders (unless another user will put a new auto-bid).
Let's say no one had put a new bid until that time, so now it is user-B turn to put its last bid (100K).
Another suggestion that could be added to satisfy the online biders (although I think that there is no reason to do so, as the game is BB managing, as I already wrote) is to define half of the auctions to allow auto-bids and the other half not...
Again, I believe that this game is not about live auctions but about BB managing.
As such, an auto-bid system is an necessity, and in my opinion all auction should be such.