(I posted this earlier in the week and then couldn't figure out where it went. It has been located and placed in its proper location.)
Mark Rosewater, the head of R&D for Magic the Gathering, wrote this really neat article about collectors and how it applies to designing collectible games like Magic.
I agree with him on most points and can really indentify with him, since I've also got a weakness for collecting superhero action figures. I have a fairly decent collection of the old "Superpowers" line from the 80's. I've even thought about buying some of these DC Pocket Heroes for the same reason he did: They're small and easier to display.