I think that would mostly be determined by the sellers description of the item. If they called it excellent and it was less then that, then the seller should be responsiable. When I sell a item and the gliding and or the Glaze has even grazing in it, I state that in my description. The seller should write a description clearly to included all this. With all that said. I would first write the seller and at least inform them of your dissatifaction, and based on their reply I would determine the next step. If they are nice and are willing to work out a fair resolution, then make the deal and leave a postive feed back or at least neutral, if they are less then nice about it, well negative feedback is warranted. As a seller I always work out a good deal, and thus far I still have 100% because of this, and believe me a few times, I had to give money back and let them keep the item.