Here's an example: I pulled a 2008 Topps Chrome Chad Henne 1/1 plate auto boxtopper
I figured I'd get around $100 for it based on comparable cards (not Henne, but taking about 80% of the value of a recent Matt Ryan Chrome plate auto sale). I put a BIN/BO of $275 to field offers. Someone grabbed it at the BIN price. Who knows what I could have gotten for it.
That's the type of thing this guy is trying to avoid.