Some people have a "collector" mentality, and others have an "investor" mentality, and the two never understand how the other buys.
The true collector, like Holiday or Mel, or Thierry, want EVERY single say, Sarah Jessica Parker one-sheet, so that this part of their collection can be "complete", and they might pay far too much for a title they are "missing" because it represents a hole they want to fill (nothing Freudian there!).
The investor sees a title like a Jaws one-sheet, and thinks it is woefully undervalued, and that it should and will be $1,000 before too long. He keeps buying them over and over because he thinks he is "making money" with every purchase (whether he is right or night is something else entirely).
When I started an investment club in 1989 (where friends of mine and I put up a cool million dollars and spent it all on posters we were buying solely for investment) I made the decision to buy the "best of the best", and primarily items from the 1910s to 1930s.
I turned my nose up to titles like This Gun For Hire which were then $2,500, because they were too "common" and besides, they weren't nearly as likely to go up in value as the 1920s and 1930s greats. I also did not buy many 1960s titles (one of the rare exceptions was when I bought 10 Breakfast at Tiffany's half-sheets for $25 each, and 100 Breakfast at Tiffany's lobbies for $5 each).
Had I instead spent my million on the best of the 1960s, 1970s and even recently printed 1980s, like James Bond, Clint Eastwood, etc, I would have made a fortune.
The problem was that I am a collector at heart (as Rich is) and I "invested" like a collector, and the two should never be mixed!
And maybe a few years from now Jaws will be viewed as a visionary who was far ahead of his time, rather than some crazy wacko!
Bruce