Your kid will have a better education and opportunities-outside-Springfield at Central doing IB. And will also be around all kinds of kids from all classes, races, etc.

However, if your kid can survive the rich kid bullying and actually make friends, they'll be well connected for a life in Springfield later on. There's a big if in there though. (And like, just having money isn't enough. If you do not, on a visceral level, know the social difference between being a Hickory Hills member, a Highland Springs member, and a Twin Oaks member, navigating the Greenwood social scene is not for your family.)