[officemonkey]

I think it may be on the same spectrum that hoarding is on. When someone collects something from their childhood, nostalgia is a potent factor. Often the thing they're collecting is something pleasant from their childhood/youth (be it X-men comics, or baseball cards, or girly mags.)

Once there's a large group of "needful" collectors, the other collections (the kind that want to make money) show up. If an item becomes "hot" with needful collectors, the speculators will buy it up, creating scarcity and driving prices even higher.

This works out pretty good, until a disruption happens in the market. Sometimes the market gets flooded with low-value merch (how many X-titles were there?) Sometimes a couple of movie bombs ruin the property (exhibit number 1: "The Fantastic Four.")

You see this disruption in the "real world" too. When was the last time you saw a "used CD store?"

But for the "needful" collectors, the value is in having the thing. And the more the thing costs, the more value people place in having it.