I quickly found out that plenty of people still care about GL and other masked marvels, both as a source of fun and a source of profit. According to Milton Griepp, who watches the pop culture business for ICv2.com, the American retail market for comics and graphic novels reaches about $400 million a year. Superhero comics, by far the most popular type, account for 70 percent of that figure, followed by Japanese-inspired manga comics and other specialized genres. Periodical comics, issued monthly, bring in about 60 percent of retail revenues, and graphic novels (comic books in book form), which Griepp believes will one day surpass periodicals, account for the remaining 40 percent.

And then there are the collectors. It's hard to get exact figures; there's no Nasdaq of vintage comics, and many large sales come from private collections. But Jeff Smith, who was a cataloger with Heritage Comics, says the company has sold $30 million to $40 million worth over the past two years, including a record-setting $5.2 million auction involving the collection of actor Nicolas Cage. At that auction, one fan/investor shelled out $125,000 for an All-Star Comics #3, which chronicled the first appearance of the Justice Society of America.

Stephen Fishler of New York City-based Metropolis Collectibles says the used-comics market could be as large as $100 million a year. According to Fishler, many investors prefer comics, "a hard asset," to the vagaries of the stock market. Metropolis has sold numerous copies of Action Comics #1, Superman's 1938 debut, for prices ranging from $125,000 to $250,000, depending on condition. A 1963 Spider-Man #1 in "horrible" condition could fetch $300, says Fishler, while a near-mint copy couldn't be touched for less than $75,000.