I have been a buyer/seller on Ebay since 2000, with over 1500 transactions and feedback of 100%. As a seller I can pretty much list an item anyway I want and people know they can count on me. The last few things I have listed, I went the BIN route. I researched sold items to get a fair price that I could live with, added in a shipping price that covered most of the US, and added free shipping to the auction. What it did for me was eliminate all the questions from buyers, and sell the item quickly. Already had it boxed, just had to drop it off at the post office. The last items I listed were higher end stuff and while I made off really good, the buyers were very happy as well.
As a buyer, I like BIN for most things. Look for a fair price that includes shipping and it's in the mail to me the next day. If it's something I really want, and it is rare, I am more than happy to try and snipe it at the last second.