First off I am not sure it costs $850 a year.
There used to be a tax advantage (paid no property tax) but that is now gone and you also lose the approx $150,000 assesed value break. HOWEVER your corporation protects your house in case of a law suit (like you hit one of those moto drivers or worse) as you do not own it,but rather your corp does.
Secondly it precludes your estate (corp and its holdings) from going through probate if god forbid you depart the real world and allows the property to be transfered much quicker and with less taxes to your heirs.
We carry our property in a corp for those reasons.
Bob K