I once traded a Jungle Rhyhorn for a Venomoth. It was the funniest thing ever. Every time the kid saw me afterwards he whined "i want my venomoth baaack." Literally, every time. I could be chilling at the park with some friends, he could come up all "i want my venomoth baaack." We could be playing cops and robbers, he gives away my position, "i want my venomoth baaack." I could just be playing a match, "i want my venomoth baaack." I never gave it back. One time I asked for another rare card in exchange, which he refused. Another time I had the card on me, and he was whining, so I was like "You want it back so bad?", crumpled it and handed it to him...only to pull it away afterwards. "Psyche!"
Later, I traded him some uncommons for a Blackwater Gyarados. Remember those? They are aka a fake non-holo Japanese one. But later, I traded that for a real one. He knew it was fake, but he also thought it was sweet. So not really a ripoff, but something I need to make a note of all the same.