If you want a few guys for security at any given time, and you want security 24/7, and you need security at multiple locations, then this all adds up really fast.

3 people in three shifts is 9 people needed per day. Given that people aren't going to work 7 days a week, you need extra people for coverage and weekend shifts. Let's be conservative and say 15 total. This is per location. Office, house, second house. That's 45 people. That's $266k per year in cost per person. Given the expenses of the motor pool, motor pool maintenance, travel accommodations and expenses for personal, the admin overhead of managing 45 people, etc etc this sounds fairly reasonable to me. If I was a billionaire I'd be spending at least that much too.