Canceling your auction because the ending price was to low and using the excuse that when they checked their inventory the poster must have already been sold because they couldn't find it. But, really almost any excuse will work. Ebay never goes to fight for the bidder in these types of cases.
I hate it when the seller charges $20, $50, and even $100 for shipping just to make their profit in a sneaky way instead of just listing all the profit in the original item. Half the time you pay a ton of money for shipping and handling, then when it shows up at the door it is packaged in gift/present wrapping paper tube that is so thin you can dent it by just holding it. I pretty much hate it when I see shipping and handling charges in excess and then it shows $1.80 on the package when you get, it's like dude, it really costs $30 for you package the thing, come on.
When the seller falsely advertise their items saying one artists did it when everyone knows good and well it wasn't done by that particular artist. But it helps get their item seen because they are hot at the moment. That is a shame because you never know when a newbie will buy it thinking it is what it is stated as. I see this a lot with Tyler Stout stuff right now, but it's been done with others before.
Chad