Two months earlier, the Henry Ford Museum in Dearborn, Michigan, bought one in better condition for a record $905,000. Another of the iconic machines, this time in pristine condition, could beat that record in a Bonhams sale in October, Hatton says. The owner bought it new in 1976 for $666.

Metropolis

Movie posters got a boost in January 2013, when a German poster of the Fritz Lang 1927 dystopian classic “Metropolis” sold for $1.2 million. One of only four known copies, its owner bought it for $690,000 in 2006 and it was put on the block when he declared bankruptcy.

The winning bidder was Ralph DeLuca, a 39 year-old collector and dealer who quit his job in finance 16 years ago when he decided he was better off putting his time and money into posters. “I shifted to tangible assets and they have been a tremendous investment,” said DeLuca who said he has received an offer of $2 million for his Metropolis.

You don’t have to be a millionaire to participate. Original British posters of the James Bond movie “You Only Live Twice,” starring Sean Connery, sell for about $1,500, while a pristine “Dr. No,” the first film in the franchise, can fetch more than $15,000.

Whether it’s comic books, Chateau Lafite wine or ancient Greek coins, the overwhelming majority of collectors are men. Not so with handbags. In that world, the Hermes Birkin rules supreme, and you don’t have to wait decades for a profit. The bags are so hard to find in the company’s shops that they can be flipped quickly for as much as triple their sticker price.

Birkin Bonanza

“You buy it on the primary market and sell it in auction,” says Caitlin Donovan, a specialist at Christie’s handbag department in New York.

A matte white Himalaya Niloticus crocodile Birkin 35 with palladium hardware sold for 157,000 euros ($172,700) at Christie’s Paris in March, more than three times what the owner paid for it new in 2009. In June, a fuchsia crocodile Birkin with diamond and gold hardware sold for an auction record of HK$1.72 million ($223,000) in Hong Kong.

Rare Leicas