From the people I know who have listed farms, their attitude is one of "if it sells, it sells. Otherwise we are happy to stay here". People do not tend to move in and out of SP like they might do in other areas. If you have been here for less than 15 - 20 years, you are a newcomer. :O)
I am sure that there are sellers who need to sell and will negotiate, but SP is such a unique place (near major cities, but still in the country with a darling downtown). All the big markets, car dealers and fast food chains are in Aberdeen, thus allowing SP to retain the same feel it has had for decades.
And, yes the Foundation... 4000 acres to ride in and enjoy. Not something that other horsey areas have.
My mom died in 2009 and her farm was sold in 2010. The farm had been appraised in 2007 at $2m, and we got about $1.6m, so about 20% down. It sold within 2 weeks at that price.