I must echo the question others have asked; if you pay 20K in property taxes, yet have been debt free for 20 + years, you have to be sitting on one hell of an asset.
Hate to say it guys, but in lots of places in this country, a $20,000 property tax bill would not be all that uncommon, and you wouldn't need a $200 million home or anything close to it. I live in the city of Annapolis, Maryland. Somebody in Annapolis with a $3 to $4 million dollar (assessed value) house on the water -- and there are plenty of those -- would be right in that neighborhood. If you bought that house 15 or 20 years ago, you are sitting on a nice slug of equity in today's market. But if you are a boomer looking to live there through the early years of your retirement and then maybe sell it to finance the later years, you better hope there will still be a good supply of folks with plenty of cash around to take it off your hands.