When people were selling houses in Detroit at the bottom of the housing crisis for $1000, the people buying them were expecting the value to rise in the future.
It's almost like profiting off of fear not greed.
People buying houses in Detroit have an investment thesis that there will still be people living in Detroit and they will still need houses, and even more broadly, that there will be more people needing more houses than there were at the bottom of the housing crisis. They may be right or wrong, but there's still a thesis based on fundamentals.
People buying unbuilt houses in the middle of the Everglades [1] because they heard of prices doubling or tripling within a year is speculation, and many of those areas still have not regained the value that investors paid for them, almost 100 years later, and probably never will.
If the price of something is higher than the "fundamentals support", that price will adjust because there are literally billions being traded every hour.
You could say that the price of land in the Everglades is set because of unsophisticated investors, with relatively little money at stake. They can't be compared.