Just in my personal experience with listing with BIN's:
If listed somewhat above the amount I would actually accept I usually get the item sold with a BIN, a "Best Offer", or an off ebay offer. As mentioned above, if I don't get it sold in the first day or so, it rarely sells later.
If the items don't sell and I list them as an auction, it's about 50-50 whether they sell for more or less than my BIN.... the conclusion is:
I have no clue what is best.
