I think that would be the same as buying highly volatile Internet stocks. :)
While the sites "status" within the search engines is a top factor in determining value, it cannot be the only one. As soon as that domain changes hands and the "meaning" of the site changes, there may be issues for the buyer. There are all sorts of variables at play here. I've seen instances (reported here at WebmasterWorld) that as soon as the WhoIs changed, performance of the property purchased suffered. I don't know if that is a given, but I surely wouldn't purchase a website based on its Google status alone. That's one BIG EGG!