Best ROI for expensive primary residence?

[Tyler D.]

I'm a veteran and have the unique opportunity of not having to pay property taxes on a primary residence of up to $2.5m (in Cook County). I am debating the best way to take advantage of this.

The most obvious would be to just buy a nice SFH and live in it. This would be a savings of about 50k per year in taxes.

I'm also considering buying a nice fourplex. The rules require that it must be my primary residence, and not rented out for more than 6 months/ year, so this would open up the opportunity to airbnb out units at select times of the year. 

What do you think is the best way to take advantage of this opportunity?