Obviously, selling on e bay is always a gamble for both parties. Winning bids on items can vary wildly from week to week just depending on who is looking right then & there , and how bad two people decide they want it. I have listed things in the past that sold for way more than I ever would have guessed, and conversely I have listed things that I thought would do OK, but never got any looks, so who knows?

A seller who enters a Buy It Now option is hoping the BIN price is more than the price if the auction went to its conclusion;the buyer is hoping that they can BIN for less than if the auction went to the end.

Personally, I would not end an auction if asked to add a BIN, if there was already a bidder ; I would wish the person who asked for one Good Luck and to bid like anyone else.

As far as sniping goes, I have no issues with it whatsoever. It is actually a good procedure for a buyer; if you bid your max very early, you end up being very suceptable to "nibblers" who keep driving your bid up a couple dollars at a time. By sniping, you can hope to catch some of them unaware. As long as one knows what an item is worth to them and bids accordingly you will never be upset if you lose to someone else. As a seller, I don't really care what method people use to bid as long as they keep bidding. I think some people fall in a trap when they lose to a sniped bid by $1, so they think "I would have bid a couple bucks more had I known" The reality is that you have no idea how high the other person would ultimately have gone.

I don't sell bike parts, but I once sold a plastic model car kit on e bay that I had for many years. I figured if I got $40 for it, I would be thrilled. There were 2 bidders who kept driving the price up with a bidding war against each other. The funny thing was there was another auction for an identical item going on at the same time. Instead of one buyer going after one item and letting the other guy have the other one, they bid against each other in a frenzy on both of them simultaneously thus driving the final price on both to just over $200. If one of them had asked me early for a BIN, I very likely might have set it at $40 which as things turned out would have been a big mistake on my part.

The funny part was, if you looked the next month, some of these kits were sitting there at the $30 level with little interest from anyone.