That is the best circumstance, Bill. When I sell w/BIN-BO I set a floor below which all offers are rejected, a range at which I want to be contacted, and an automatic acceptance level at or above which the offer will be accepted instantly. IMO the BIN-BO tool is one of the few really useful things Ebay has come up with.
As for the original issue, I agree w/Larry that it depends. I'm usually going to try and shave a % off the price when there is a BIN-BO but I've also jumped on specific items at the BIN when I know they are very difficult to find and I am afraid they will sell and I never look back when that happens w/any price regrets. A very wise collector [well, Leon, anyway
] once told me that for a rare card it isn't worth sweating over a hundred bucks. This Israeli Cassius Clay card is rare and had a BIN that was probably reasonable but I was nervous as to whether it would ever get here (my luck w/foreign sellers has been crappy) so I offered 25% on it instead:
This thing, on the other hand, just as rare, offered by a domestic seller had a very reasonable BIN and I didn't bother with the offer since I knew what it was and how hard they are to find (nearly impossible, actually, as it is a proof sheet and ESCo typically saved only a set or two of proof sheets in its art file for each issue):
