I've dealt with a few people who play the bidding game. They'll sell something for $150 and say that someone really wants it and is coming by this weekend and they're offering him $200. They'll also say that they're willing to sell it to you for $200 if you come by right now. Most of the time they're just lying about the other potential buyer to jack the price up a little more. If you decline most likely they'll come back to you in a few days and ask if you still want it for the original asking price.
