2. Action Comics #1
For you non-nerds who don’t know the relevance of that, Nic Cage owned the first appearance ever of Superman in comic books. It’s a comic that is rumored to be in the two million dollar price range. Cage is known as an avid dork (i.e. collector of nerd things), and was even nabbed to play the Man of Steel at one point for a Tim Burton film.
While buying nerd things in itself is not bad, buying them as haphazardly as Cage did led to a financial downfall of epic proportions.