A lot of people call my (parent's) house a castle. It's weird how perspective changes. The ironic thing is my mom had a chance to live in an *actual* castle, but that's a long story.
Ahem, anyways, my area has quite a few pretty nice houses. We've got some mega-rich people, but they don't build anything too extravagant, which I think is weird. I sure wouldn't hold back if I were the leading manufacturer of tennis balls, or head of a hotel chain, etc. That being said, they may not be huge houses, but the property they are on is expensive just because of the area. It's unfortunate because a lot of upper middle income people have had to move off of the area because it's taxed like mad. My parents got off easy because we're across the road from the lake instead of on it.
My dad also built most of our house himself, they're anything but rich. Middle income.
Anyways, that doesn't have much to do with the original question..I guess i'd say...9,000 square feet definitely does it- less if it has a lot of style.