Quoted from shlockdoc:Why would a seller add OBO to their price when they are not looking for offers and get insulted. That’s my best offer. At least an offer was made. A simple too low or counter offer would be respectful. Why is that too much to ask. Why not say firm?
because some here don't know what OBO means. They think it's just a pinball term like NOS and things sell better if you put that in your description.