They're a little off, but not much. The problem is that most people can't build a 5k sq ft place on a 7500 sq ft lot without going down as well as up. Basements in the Palo Alto flood zones are crazy expensive to build and permit so most don't do it, opting to stick to the sq ft requirements, which on a 7500 sq ft lot would be ... 3200?

5k would need a 10k lot in palo alto. A 10k lot in palo alto goes for 3m to 5m depending on neighborhood.

So , yes, it's nuts.