Should I steal a kids yu-gi-oh cards?
Are you joking? Why would you steal a kid's yu-gi-oh cards?
Because he has the rarest cards in his collection
You shouldn't steal from others. If you steal then they can report you and would be in big trouble.
It is not so much stealing as me not paying him a lot. He may regret not charging me a ridiculous amount for cards.
When underpaying something that you know is worth a lot, people would consider it stealing. It is bad to steal especially from a kid.