Some superfans will pay for literally anything owned or used by their favourite celebrity.
Earlier this week, a charity shop in the UK offered up Ed Sheeran's tattered old slippers, and while we might be wondering why anyone would want them at all, the shop is hoping to get as much as $360 for the well used shoes.
The list of weird and gross celebrity memorabilia fans have spent good money on is bizarre and disturbing.
Brace yourselves, it only gets creepier from here.
ITEM: BILL SHATNER'S KIDNEY STONE
SOLD FOR: $25,367
Yes, you read that right. Captain Kirk sold his own kidney stone at auction in 2006 for over $25,000.
The lot also included the stent and string used to help him pass the stone, and was purchased by online casino GoldenPalace.com.
Shatner donated the money to a housing charity.
Kidney stones, which can be staggering painful if they grow too large, are a build up of crystals formed by your blood's waste.
According to Shatner, this particular kidney stone was so big "you'd want to wear it on your finger".
Well, you might not want to, but I guess you could.
ITEM: BRITNEY SPEARS' USED PREGNANCY TEST
SOLD FOR: $7410
In 2005, the same online casino that snagged Shatner's kidney stone did it again and forked out $7410 for Britney Spears' used pregnancy test.
The positive test, allegedly used by Spears, was found in a Los Angeles hotel room bin after Spears' and then-husband Kevin Federline's stay.
The pop star neither confirmed nor denied if the test was hers, but it's believed the test was the first sign of Spears' oldest son, Sean, who was born in September the same year.
The $7410 the casino paid for the used test was donated to charity.
Considering someone on eBay paid $20,000 for a piece of gum Spears spat out, that's not a bad price for something the star had peed on.
ITEM: ELVIS PRESLEY'S SOILED PANTS
SOLD FOR: A bid of $9060 was rejected by seller, who wanted at least $12,680
Elvis Presley was a well dressed, well coiffed man. It's understandable fans would pay a few thousand for his jumpsuits or jewelery.
Where you lose most of us though, is at his dirty underwear.
That didn't stop a Stockport auctioneer who, in 2012, tried to sell a pair of unwashed underwear the King apparently wore during a performance in 1977.
The sweat stained (yes, sweat stained) briefs were expected to get the seller a cool $18,120.
Surprisingly, one super-fan put in a bid of $9060, but the underwear didn't sell as no one was prepared to meet the $12,680 reserve.
ITEM: 'QUEEN ELIZABETH'S' KNICKERS
SOLD FOR: $19,932
The King's undies aren't the only kinckers up for grabs.
A pair of silk underwear, believed to have belonged to the Queen of England, sold for more than $19,900 on eBay in 2012.
Apparently the royal undies, embroidered with a crown and the letter 'E', were left on a private plane Queen Elizabeth used for a trip to Chile in 1968.
It's said the pilot took the knickers and gave them to his friend, a Hungarian aristocrat.
The knickers were later sold as part of the artistocrats estate.
The owners, who listed the garments as "previously used" said it was the buyers obligation to authenticate before bidding.
Buckingham Palace refused to comment.
ITEM: JOHN LENNON'S TOOTH
SOLD FOR: $35,334
The Beatles have some of the most extreme fans, and memorabilia, in music history.
Back in the 1960s, John Lennon gave his tooth to his housekeeper, who's daughter was a Beatles fan.
Fastforward to 2011, that tooth was purchased by Canadian dentist and avid tooth collector Micheal Zuk.
Lennon's tooth was yellow, brown and had a cavity in it. Zuk bought it for $35,334.
"Once I heard it was up for sale I had to have it. Some people will think its gross, others will be fascinated by it," said Zuk.
But what does one do with a celebrity tooth? Zuk announced last year he would use DNA from the tooth to help those claiming to be Lennon's love children in order to get part of the singer's $724m estate.
ITEM: LADY GAGA'S FINGERNAIL
SOLD FOR: $15,402
In 2013, one of Lady Gaga's "Monsters" paid an incredible $15,000 for one of the singer's acrylic nails.
One of Gaga's roadies found the nail after a Dublin concert and decided to auction it off.
"I noticed an object on the floor of the stage, which at first I thought was a guitar plectrum." The seller wrote on the listing. "When I picked it up, I saw it was an acrylic nail."
ITEM: SCARLETT JOHANSSON'S USED TISSUE
SOLD FOR: $6523
During a chat show promotion for her 2008 film Spirit,, Scarlett Johansson used a tissue twice to blow her nose.
That mucus covered, lipstick stained tissue was signed by Johansson, bagged and then auctioned off on eBay where it sold for over $6000.
Johansson needed the tissue during her appearance on The Tonight Show because she's caught a cold from Samuel L. Jackson, joking that it gave the sickness more "value"
Johansson donated the money from the precious tissue to USA Harvest, an American hunger charity.
ITEM: JUSTIN TIMBERLAKE'S HALF-EATEN FRENCH TOAST
SOLD FOR: $1518
Justin Timberlake's not one to let food go to waste.
In 2000, at the peak of NSync popularity, Timberlake was given some french toast during an interview for a breakfast radio show.
He didn't finish the meal, but signed the bread and allowed the DJ to sell his leftovers.
Kathy Summers, a 19-year-old Nsync super-fan, handed over $1518 for Timberlakes table scraps.
What's a teenager going to do with a pop-stars half-finished breakfast, you might ask?
"I'll probably freeze-dry it, then seal it … Then put it on my dresser," she said.