Nerdy Valentines Gift?

Okay, I’m in high school, Valentines Day is coming up and I plucked up the nerve to ask my crush casually to be my valentine. He said yes, but I think he kinda sees it as a friend valentine. Either way, I think it would be sweet to get him a small gift in around the $10–20 price range. The two of us battle in Pokemon and we YuGiOh duel a lot, so I wanted to do something cute concerning Pokemon or YuGiOh. I’d really appreciate it if I could get some suggestions for this.