Then I noticed he was selling the exact same model of laptop so it was easy for me to realize that he had just "bought" my laptop to remove the listing so it wouldn't compete against his. I messaged ebay support to accuse him but they didn't do anything about it.
Since he had made the order, eBay did show me his shipping information so I ordered a "glitter bomb" which was basically glitter in a tube with a spring. I got a very nasty accusatory email from him, but it was very vague. He wouldn't specify what he received, but that he was smart enough to not open it. That's how I knew he got the full effect.
I just replied something to the effect of "You never paid me. Why would I send something to you?"