There was a thread like this a while ago. Supposedly the rare stuff is usually near the end of a console's lifespan and doesn't have a lot of praise. I really don't think it's something worth attempting, though. Just play what you enjoy and don't worry about what will appreciate. Chances are the opposite will happen with most games and you'll find yourself in the hole.

I do wish I had that "video games are not an investment" pic from the last thread right now...