Hmmm … with 10 million in the bank, why not just buy outright and not have a mortgage. I actually don’t think that the mortgage interest deduction is worth it. You’re still paying the bank interest. Seems to me that you only come out ahead if the money you were going to use on the mortgage generates more income than the interest you pay (factoring in the tax break). Looking at the investment options available today, that seems like a dicey proposition. Plus, there is the possibility that the mortgage interest deduction will be eliminated.

Income from $6.3 mil should cover about $200K in expenses per year. So $10 mil should be enough to buy a $3.7 mil house.

For me, if I really liked the house, $5 mil in cash would be enough for me to buy. Income from employment would cover living expenses. There would still be a $1.3 mil cushion. That’s a heck of a lot more than the majority of Americans have as a cushion (even accounting for the increased expenses of maintaining a $3.7 mil house). Anyway, this is all hypothetical for me. Just curious what everyone else thinks.