Garage Sale Etiquette?

Last Saturday Pompton Lakes had it's annual Town Wide Garage Sale.  We participated and I must say, it was my first real garage sale experience.  We joined 2 other families at 1 of their houses.  If not for the company, I would have been miserable.  Watching the collection of characters who browse garage sales is entertaining, but in the end, frustrating as hell.  Most are looking to barter, regardless of the price of an item.  I was amazed by how often someone would ask about an item they were obviously interested in, then walk away after hearing the price.  Our host was selling a toy Elmo kitchen, in perfect condition.  The thing was almost 4 feet tall.  A woman asked, "...how much>?".  He said, "$10".  She left.  What the hell did she want to pay???  $7, $5, $2.50???  Are you freakin kidding me?  This sort of thing happened all day.  One woman