Presuming economical access to space is going to scale up a lot in a few years, and taking the many billions of dollars, years of building, and human obstacles to building on the ground -- if it were me with the billions, I'd be thinking about creating a workshop in orbit and then building genuinely big scopes up there, where you're so much less constrained by "the whole thing's gotta fit in a booster, survive not just Earth gravity and weather but a rocket launch, and then deploy and totally work up where nobody can fix it."