The per acre analyses used by most St. Joe bulls exclude selling expenses and taxes. I believe that the equivalent gross value to the $9,000 an acre used in your analysis is the equivalent of $18,000 an acre, when taking expenses and taxes into account.
As it was, I did not quantify any amount of swampland at the Ira Sohn conference. I simply noted that some of the land is swampland. The weather is much worse than South Florida (just as hot in the summer and cooler in the winter), there are a lot of mosquitoes, there is not a lot to do, and the demographics are poor. I noted that I thought St. Joe overplayed the value of land within ten miles of the ocean and noted that I thought that vacationers would prefer to be "on the ocean." More than a mile is too far for many families to walk to the beach. Finally, I thought the airport development is the type of story often seen in promotional stocks designed to buy years of time to encourage the market to ignore current financial results. The current airport does not operate near capacity. Airports in Jacksonville an Ft. Myers did not spur a lot of development next to their airports and it is odd the St. Joe seems to believe that a lot of people will want to live near the airport, as if that is a residential attraction.