What is the "next big thing" in vintage Rolex?

[jfmiii]

I always find it interesting when I read about a watch that was saw 10 or 20 fold increases in just a few short years bc they all of the sudden became desirable by collectors. while i collect watches that appeal to me bc i want to wear them and enjoy them, ill admit that i hope that one day i will buy a watch for $5000 and watch it's value explode to $25,000 in 5 years (i can dream right?). that being said, what do you think is undervalued now that may command high premiums in the future or what is highly valued today that will be a year's tuition at Harvard tomorrow? 1675 Root Beers? Full set 1803s?