I would respond by saying - "Oh about 6 million dollars" - .

We all know that auctions are not predictable....who knows what an item is worth? It is the bidders who determine the value of an item at the time an auction ends.

I have had high quality items ...heaps of watchers & no bids...then i have had what I would could consider as a junky item and the bidders have gone into a frenzy and the item has sold for a silly amount.

To answer your question - I always respond. "Just leave a bid that you are comfortable with"