The answer to this is unequivocally Texas outer suburbs- lined with giant houses that look like what you would expect the wealthiest person in NYC or SF to live in but "only" cost $2M, so there's a bunch of them in a row.
Yeah the key has gotta be not where the wealthiest are located but locations with a number of wealthy individuals and sprawling land to keep the cost of living low. Suburbs in Texas, OKC, Indianapolis, Des Moines.
Yeah Carmel, Indiana, is a very wealthy looking place. Big houses everywhere, fancy fountains and sculptures in the roundabouts, the big European style concert hall.
