Regardless of the amount of money someone has, what the heck does anyone need 50,000 to 100,000 square feet of space for?
Indoor basketball court/gymnasium
Indoor garage/museum for 20 cars
Movie theater
Bowling alley
Disco
Indoor swimming pools (including grottos)
Maids/workers/bodyguards/drivers/cooks quarters
Waterfalls/indoor gardens
Self-contained power plants
Tennis courts (indoor to protect from the sun)
10 or more lavish bedroom suites
Commercial kitchen
Private offices
Huge wine cellar
Indoor shooting range
State of the art security center
Mens and womens steam rooms
Great room with space to entertain hundreds
Hell, 50,000 square feet is cramped!