Buy It Now -- Or Best Offer

Yesterday I was able to post a bunch of my stuff for free using a Buy It Now and a Best Offer option.  I posted the item with the Buy It Now I had originally posted and allowed an automatic acceptance of the opening bid amount.  Make sense?  For example:  Let's say last week I had a shirt up for $10 opening bid and a Buy it Now of $13.  It was going to cost another 30 cents to post it.  Creeping my fees up to 90 cents.  I went in and chose "fixed price" for $13 accepted a "best offer" of $10 for FREE.  I probably saved myself somewhere around $20 which may not seem like a lot, but when my profits are down to a dollar here and there, $20 is a lot.