As a seller, I have to confess that I'm always happy when the final price goes above the original BIN just because it completely sucks when the first bidder bids really low and causes the BIN to go away. Ebay charges at least 0.25 per BIN, even if the 1st bidder ignores it and places a regular bid. I don't mind the expense if I have the advantage of the auction ending early and getting paid sooner, but it gripes me when the 1st bidder bids at the original price (not even a penny over) I think just to make the BIN go away. I've actually stopped using BIN unless I have a Fixed Price Auction because it was getting too expensive to have that keep happening.
I think many times it's a matter of one bidder placing a bid and then latecomer bidders discovering the auction and perhaps not realizing the original BIN price was or starting a bidding war.
There is definitely abuse of BIN by sellers offering astronomical BIN prices, but sometimes, it's just the seller trying to re-coup their original investment + a little extra to cover fees, etc.