If an item is fairly priced, it will sell. A little dickering is fun. Too much dickering is offensive. Often, asking "what's the best you can do on several pieces" will result in a happy seller and a happy buyer. If you are told, "I can't do that," its time to decide how much you really want the item and if you can live with the asking price. A lot will depend upon how long the item is on the table [how many shows] or how current the post is.
I've met a lot of great sellers on this forum... and a few aren't so great. That's life!
Happy Holidays and Merry Christmas to all.