Most artists have their own style and find no satisfaction in copying other work.
Lawsuits are for the rich or if your going up against a well know store that is flagrantly violating copyright. I am surprised that Ebay would drop the other work, they are setting themselves up to be sued, by taking yur word and acting on it. There are a lot of items out there that are similar or in public domain and can't be copyrighted even though someone thinks it's there idea. You didn't mention what the item was, you've peaked my curiousity. This Discussion Group is monitored regularly.