I recently won a multiple offer situation for my buyer using common sense. The seller was posing as a potential buyer at his own open house to see the reaction of people going through his home. Neither my clients or the other people at the open house knew this. I always tell my clients to be neutral at showings while taking mental notes. I tell them to criticize and compliment the home when we get out the door, so we can tactfully use this information during negotiations. The other buyers at the open house 'tore the place apart' stating how much renovations the home needed and how it was so poorly taken care of. The seller was not pleased with these comments as this was his humble abode for several years.
Regardless of price, the seller was simply just insulted by these buyer's comments and did not want to entertain their offer. Thankfully, my clients were then able to present a fair offer without competition, and we got a fixer upper for a great price. Remember, the listing agent is working for the seller so be cautious with your comments and reactions when you're viewing homes.