“This house includes the land for $97/sf. Does that mean that the land has negative value?”
No it means it was a stupid place to build and worse yet, pay an astronomical price for a oversized house. An appropriate house for most people who can actually afford and want to live in Menifee, shennanigans put aside for the moment, is about 1200ft sq. Sooner or later those people are going to be getting a free 2000 sq. ft.