When did collecting turn into a way of investing and making money?

[Exhibitman]

I attended my first show in 1976 and was setting up at shows by 1978. It became an investment around the time the first price guides came onto the market and took off when (1) the key 1950s rookies and desirable cards soared in price and (2) modern rookie cards became a craze. By 1980 the race for cardboard gold was on in full force. I recall buying a 1953 Topps Mays for $25 in 1976 and being able to flip it for $500 in 1980. 1981 marked the start of the multiple issuer modern cards and the Fleer error cards like the "Craig" Nettles soared in value. Then came the rookie card thing, which hit its stride with 1984 Donruss and Don Mattingly and peaked with the 1989 UD Ken Griffey Jr. I'd characterize that as more the penny stocks phase of things; lots of people made money on short term trades of rookies but anyone who held on to those cards thinking they had a nest egg were sorely disappointed [should have invested in a solid American company's stock, like Braniff Airways]. Since the hobby has spawned full time dealers, price guides and the National it has become an entrenched business. There was an [in]famous Sports Illustrated artice about Alan Rosen and another study by some economists that determined one of the best ROIs over a decade had been old baseball cards. People who are in the business of selling the general public stocks, bonds and other casino bets grudgingly will admit that baseball cards, art and other collectibles are "nontraditional investments" but will advise their marks, er, clients to allocate no more than 10% of their investment money in it. Ebay was another boon to it IMO as it adds liquidity to the market and eliminates middlemen. It is possible to engage in the equivalent of short term trading with Ebay: spot an undervalued or misrepresented item, snag it, flip it.