Whether anyone has the authority to sell acreage on the moon... that's an interesting debate.
Whether it's a good idea or not... are you serious? You'd have to be incredibly short-sighted and close-minded not to realize the potential there. Someday, the moon will be utilized. It might not be inhabited, but it will be utilized for something. It might be centuries down the line, but it will happen. And those who make big real estate purchases early will be viewed as cutting-edge geniuses when their companies or descendants start making money somewhere down the line.
You know, when the United States made the Louisiana Purchase, people thought Thomas Jefferson was a fool. "What are we going to do with that land? Who's going to want to live there? It's wild, uninhabitable country."