Slate has a disturbing (for those of us who grew up collecting baseball cards in the 80s) excerpt from the book Mint Condition: How Baseball Cards Became an American Obsession. The gist is that all those cards I fawned over as a kid are worth nothing, mostly due to the fact that they printing an estimated 81 billion cards a year at the peak.
Anyway, one of the more interesting (to me) snippets from the article is about Beckett Magazine, which was THE guide for card prices:
What none of us understood at the time was that Beckett’s guides were probably creating card prices just as much as they were reporting them. When Beckett sued a competitor over copyright infringement in 1979, claiming that the rival had stolen his data, the judge noted that because Beckett’s guides were “regarded as the authority in the field, it is entirely possible that the prices in [his] publication not only reflect market prices, but in fact can determine market prices.”