As someone who has had kids in both, I can share my perspective having taken this journey. Here in MA, we have some of the best private schools like BBN, Dexter, Groton, Philips, etc. Their cost is prohibitive coming in between $35K to $50K per year per child (this was a few years ago so may be more now). In all honesty, the campuses were nice, teachers pleasant, but I was not impressed in general. They do retain one major advantage as the top private schools serve as feeders for top colleges and universities. In short, if you go private, go big.
I feel moving to a town or city with excellent public schools represents a better value. The real estate will cost more, but nowhere near the several thousands of dollars per month a top private school will cost. The real estate will also appreciate with time. Another option is to look into whether a good charter school serving your area exists. If your child is in a higher grade or the charter school already saturated with children from your city/town, this may not be an option.
You get more by going with an excellent public or charter school as suggested above and taking the remaining funds to not only invest in a trust as you suggest, but to enroll them in extra curriculum activities such as math, chess, music, and literature classes. For example, The Russian School of Math has locations across the country and provide an excellent math education for about $2K per year per child. This math curriculum will far exceed anything your child will learn in any school, public or private. It is classical, but this style math was good enough to put people into space several decades ago.
In the end, what matters most are starting early and the parents. Although a top private school increases the odds of getting into a Ivy League school, it isn't a magic bullet. Any parent who puts in the sweat and blood proving resilient and persistent in ensuring their children keep learning in select areas will do the trick. That said, one must also be careful not to burn their kids out by being selective of any extra activities and remember to sometimes let kids be kids.
In any case, that's my opinion for whatever it's worth.