Interesting topic, but I think you have way underestimated the cost of these items. For a $20 million house, for example, with a property tax rate of 1.1% in Beverly Hills, you would pay $18,333 per month in property tax. Another $8,333 per month in insurance. That is $26,666 per month only for property tax and insurance. That does't include maintenance, utilities, cleaning, gardening, etc. It would take way more than the $30k per month you suggest to live this life.