People who put OBO in their ads are more likely than not going to end up being dishonest when all is said and done. If you list game for 6K and the best offer you receive is 4k, then you should sell it for that since it was in fact the best offer and your ad included an asking price OR BEST OFFER.

When you advertise that you'll take "best offer" and then don't, that's stupid. Otherwise, it should be called an auction with a reserve. I realize that in reality that that's not how it really plays out, but it should. Otherwise, why say OBO if you don't really mean it? Or perhaps you should say "OBO unless you're offer is less the $X, then don't bother" or something to that effect. Otherwise, OBO means that offer is game.

Well, of course. A lowball offer with other and better offers was never the best offer to begin with.

That's it. It simply means different things to different people. The way I take it is clearly not the norm- haha. It's all pretty moot for me anyway because whenever I've sold a game, I've made sure that it was the lowest price for comparable condition around because I don't like to waste time on tire kickers. When it's time to say goodbye a game, it's time to say goodbye. I've never needed to anchor my price with OBO.