Applying to all the Ivies is often prestige-based, which is not the best of reasons but very common. These schools are all different.
Financial aid should definitely be a factor so that is one good reason to apply to Harvard, Yale and Princeton. I don’t know about aid at the others (when my kid went to Brown, they still had loans and no longer do).
Check out Amherst and Williams as well, for financial help (and prestige!).
I would make sure to learn about other great schools out there.