How much is this? one might ask. It's...$27.6M - what a coincidence - and it's on...1.97 acres. That pencils out to...hmmm...carry the one...$14.01M/acre.

Except, of course, that the price that one lists something at is not necessarily the price that one sells something at. Especially if it's been on the market for more than a year.

So let's look for something that's sold. One block down from your example, we have a home that just sold a few days ago. Also for $27.5 million, coincidentally - but this one is improved with a 12,000 square foot mansion on it and is on four acres:

zillow.com - S Ocean Blvd Manalapan FL

Hmmm...I wonder if anything else might be in play? Perhaps the fact that the Manalapan properties come with private beach access (each of the lots covers both sides of Ocean Boulevard, allowing the owner to have one of the rarest amenities that exists in Florida)? Perhaps because Mar-A-Lago is encumbered with a historic preservation easement, which prohibits not only changing the exterior (which is burdensome but common for single-family residential historic properties), but also portions of the interior? Or the deed restriction which prohibits it being used for anything but a private club, which is an extraordinary burden on the Property?

Let's look at what the Property Appraiser has done for your property. Hmmm...they appraised the land value at about $15 million - which is pretty close to the market price that this seller might get for that land.

pbcpao.gov: Property Print

So the Property Appraiser got the appraised value approximately right for your example - but is off by 1800% for Mar-A-Lago?