I've only ever lived in New York and Texas. In NY, the 8 acres we have now is quite small for the boarding facility we run (and even then, we only have around 10 boarders). And in TX, most people with horses/barns would consider 20 acres small! Haha.
I think some people are taking what I'm saying the wrong way, though. I'm not just looking for a backyard barn for my horses. Once I retire, I'd love to have a "fancy schmancy" barn, as you put it. Yes, I'm aware that it's more the reputation/trainers than the property that make a barn 'fancy,' but we have a reletively fancy show barn now, so I'd like to continue on to have my own in the future.