It wasn't BIN, it was an auction with one bid. It's a mystery! Anyway I think the concept still holds true that you can get some BIN steals.
Even if it were an auction that ended normally, it wouldn't carry the "This listing was ended by the seller" message. If a seller ends an auction early without cancelling all the bids first, eBay's policy is that the item goes to the current high bidder at the current bid price, at least the last time I looked. And this one was put up as a 10-day auction, but ended a bit less than six hours after it was listed. But, yes, you're right, you can definitely get BIN steals if you watch long enough. I've posted quite a few here over the years.
Haha I just read the story about this coin a few days ago. Now let's consider the opposite scenario where someone sold their 1975 proof set containing a no-S dime for $10.