[pwcosol]

The entire issue is a difficult call. Competition for desirable collectables can be intense. Yes, in a world of "fair play" the seller would follow Ebay protocol and see the auction thru. All interested buyers could bid and he whom is willing to pay the most becomes the victor. Unfortunately we do not live in such a world.
If there is a bargain or rare item up, likely some collector or profiteer will take a shot at trying to secure the item through a "back door" deal. Knowing this, don't be surprised when the piece disappears from the listings. Therefore, it is your choice whether or not to make an inquiry with the seller. The seller holds all the cards. More often than not, he will opt to continue the auction (if he is smart) sensing somebody must know something he does not about the item and it's potential value. Lastly, some sellers have taken to providing their direct email address within their item description(s), soliciting interested bidders to contact them directly if they have "a question". To me, this is a "green light" indicating the seller has other merchandise and/or is willing to sell items offline, and avoid the auction fees.