So, forget paper money, in the eventuality of the kind of event that is forecast the rise in sea levels, an economic collapse is part of the scenario. Prices will depend on how much assets people have. Prices go down in depressions, which is exactly what will happen when the climate debt comes due because people will have less spending power. During the great depression or the Weimar meltdown, when paper money became worthless, people didn't turn to gold, they turned to bartering. Gold and land will actually decrease in value because people won't have the kind of assets that they do today. As you point out, some special pieces of real estate might become more valuable but not all land that isn't inundated will.
Land like
@bluntmassa1 's which is far away from the sea and from the sound of it is not in a desirable location -- no insult intended but he isn't exactly living in a destination resort -- will decline in value because of a lack of buyers and a broken capital system. As a source of independently producing ones needs, it will be valuable to those that manage to keep it but how much butter and eggs can be used to buy land?