Should I buy the Jordan 3s a size bigger?

I am a teenage boy, and my feet have pretty much stopped growing for now. I have one more growth change to hit within the next 3 years though. I was wondering should I buy the Jordan Retro 3s in a half size bigger. Do they fit small? I can't find a place to try them on so I really need the help. I just need to know should I buy them my size or a half size bigger. I want them to last since they are a rare sneaker so what size?