CANVASES, CARATS AND CURIOSITIES

What is the value of a worn door from a shabby New York hotel, spray-painted with an X and thrown out during renovation? If the door was to Jack Kerouac’s room, $37,500. For Bob Dylan’s door, a whopping $125,000.

How about a dilapidated house that a 1950s civil rights activist spent time in? At least $1 million.

Most people would abandon items like these. But for others, the response is different: Cherish it the way someone else might prize a Picasso or a Renoir.

At a time when information on even the most obscure objects can be easily found on the internet and hobbyists across the world can connect online, some of that junk might actually become treasure.

“There’s barely a day that goes by that people aren’t presenting interesting collections to us,” said Arlan Ettinger, president and chief executive of Guernsey’s, an auction house that has staked its reputation on nontraditional objects. “Will it resonate with the public? That’s the answer to whether we go forward and sell it at auction.”

At the end of the month, Guernsey’s plans to auction off a lot of African-American cultural and historical artifacts, including the first contract signed by the Jackson 5, boxing gloves worn by Archie Moore, a marked-up manuscript of Malcolm X’s autobiography and Rosa Parks’s will and estate plan.

The house where Ms. Parks stayed in Detroit after leaving the South is also up for auction, with a reserve price of $1 million. After being moved to Germany and back again, the house is in two shipping containers in a storage facility outside New York.

Obscure historical items present all sorts of questions that a piece of fine art with an established provenance and an auction history does not. For one, if the names attached to them are not immediately recognizable, their inherent value could be in doubt. And the future value of an item can be unpredictable.

In April, Guernsey’s auctioned off 52 doors from the Chelsea Hotel, a New York landmark made famous by the artists and writers who stayed there. After the doors were thrown out during a renovation, Jim Georgiou, a homeless man and a former hotel tenant, retrieved them and began researching who had stayed in the rooms that were once behind them.

At auction, the doors — all heavily chipped, battered and marked with X’s to signify demolition — brought in prices higher than the nicest new door.

The door to a room where Janis Joplin and Leonard Cohen spent a night together brought in $106,250. Andy Warhol’s door went for $65,225, and the door to Jimi Hendrix’s room fetched $16,250. Joni Mitchell’s door was a relative bargain at $10,000.

Tucker Mitchell, an artist in Oyster Bay, N.Y., bought two doors that were not linked to a particular person, paying $5,000 and $1,000 for them. She said she was not worried about the value, though she wished she had bought a named door, like the one for Liam Neeson that sold for $5,000.

“I’ve always been drawn to odd things,” Ms. Mitchell said. “I bought them mostly as energy.”

Whether discarded items will have any value to someone else is hard to predict. And some psychologists question whether someone junk could have any real value.

“Holding on to junk with the hope of spectacular appreciation is the equivalent to buying a lottery ticket that won’t be drawn for 50 years,” said Brad Klontz, a financial psychologist in Hawaii. “It’s a form of extremely high-odds gambling that requires a storage unit and lots of patience.”

For some, he added, it may be a sign of hoarding. “Shows like the ‘Antiques Roadshow’ give a false impression of the value of old junk,” Dr. Klontz said.

Several decades ago, hand-carved wooden carousel animals were being discarded as the carousels were replaced with more modern rides. In the early 1980s, Guernsey’s organized an auction of about 90 carousel animals that one man had collected over the years. He needed to sell them to pay for medical care for his daughter and hoped to get $30,000, Mr. Ettinger said.

The auction brought in more than $1 million. Today, a single horse can sell for more than $100,000 if it was made by a famous carver like Daniel Muller, who operated a carousel company with his brother in the early 20th century.

Prices can just as easily go down. Mark McGwire’s record-setting 70th home-run baseball brought $3 million at auction in 1999, shattering the record for baseball artifacts. But Mr. McGwire’s achievement has been tainted by suspicions of steroid use, and Barry Bonds broke his record with 73 home runs in 2001.

“It’s not worth very much today,” Mr. Ettinger said. “What made it noteworthy is no longer the case.”

But sports memorabilia is still a lure for fans. Brandon Steiner, chief executive of Steiner Sports, which specializes in collectibles, sold off as much of the old Yankee Stadium as possible. Seats and signs, for sure, but also bricks, dirt and even grass from the field.

“I knew with the grass that people would love to have a piece from the last game,” Mr. Steiner said. “I made over $1 million selling that grass.”

He did well with the dirt, too, which he included in pictures, frames, coasters, pens and other collectibles at prices that ranged from $25 to more than $1,000.

Yet when asked about what they might be worth in the future, he demurred. “If you’re buying that type of stuff thinking it’s going to go up in value and you’re going to make a lot of money, you’re going about it the wrong way,” he said.

Such fleeting connections to value make it hard to determine what might appreciate and what is basically a nice ornament, like a chandelier or a sink faucet that may cost a lot but has little intrinsic value.

Carousel horses have certainly gone up in value. They are even appreciated by museums for their artistry and craftsmanship.

The doors from the Chelsea Hotel lack any craftsmanship; their value is tied to the reputations of the people who once slept behind them. But those associations with fame, like Mr. McGwire’s baseball, could rise and fall.

Of course, some stuff that seems like junk really is. Amanda Chunn, senior researcher and curator at M. S. Rau Antiques, a New Orleans shop known for odd finds, said she gets calls every week from people asking about the value of their Beanie Baby, Coca-Cola bottle or McDonald’s toy collections.

She has to tell them that they really have none, at least not from an investment point. She suggests that they try to sell them on eBay.

“It’s not to say there isn’t a market for vintage Americana,” she said. “It’s just not on the high end.”

Even at that high end, there are not that many buyers for pieces that others might consider junk. Take 92 feet of ticker tape, the spools of paper that used to deliver breaking news from around the world to newsrooms. It was usually discarded after being read, but M. S. Rau has tape from D-Day, when Allied troops invaded Normandy on June 6, 1944. It begins at 8 a.m. and ends at 4:35 p.m., Ms. Chunn said.

“We don’t know what newspaper it’s from, but someone had the wherewithal to keep it,” she said. “It reads like a novella.”

It’s priced at $38,000, but it has been up for sale since 2015.

Equally obsolete, but a quick seller, are old metal machines that individuals used to cork wine bottles, Ms. Chunn said. One in the store is priced at $12,850.

“People aren’t going to use it, but you know it’s going to work in someone’s décor,” she said.

There is profit to be made in the quest to buy and collect stuff that others might discard. Larry Moss, who owns Interstate Blood Bank in Memphis, has amassed thousands of items. These include signed dollar bills, canceled checks with presidential autographs on them, and a lot of Elvis Presley memorabilia.

In his quest for ephemera, he did buy a couple of truly valuable pieces, which came in handy when his business was struggling in the late 1990s.

The items were the white suit that Presley wore in his 1968 comeback television special and the white Knabe piano he played at Graceland but moved out when his wife, Priscilla, gave him a gold-leaf piano.

“I worked for a year and a half without a salary, and I sold those two items and supported by family,” Mr. Moss said. “There was a time when things weren’t great, and Elvis helped me out.”