Appraiser Stephen L. Fletcher, found the jug fascinating and claimed the bizarre-looking piece of pottery "dated to the late 19th century" and valued the unique piece at $50,000 (NZ$74,000).
"You even see a little bit of, like, Pablo Picasso going on here. It's a little difficult to identify precisely when this was made, but I think it's probably late 19th or early 20th century," Mr Fletcher said.
But oh so wrong!
It was later revealed the Picasso-like sculpture was actually made by high school student, Betsy Soule, from Oregon, in her ceramics class in the 1970s.
After the episode titled "Grotesque Face Jug" aired, Ms Soule received a phone call from an old high school friend.
"She said, 'you've got to get on the internet and look up 'Antiques Roadshow'. That weird pot you made is on there," 60-year-old Betsy told local paper, The Bulletin.
After this call, Ms Soule contacted the show and sent in a photograph of herself with similar pots she had created over the years.
Since then, Antiques Roadshow has reappraised Mr Barr's artwork on their website, revising the valuation to $3,000-5,000.
"As far as its age is concerned, I was fooled, as were some of my colleagues ... Still, not bad for a high-schooler in Oregon," Mr Fletcher said.
He also released a statement praising the technique of th young student, saying: "We have sold at auction several examples from the 19th century - all of which are from the eastern half of the United States, and have a single grotesque face - some for five figures."
"This example, with its six grotesque faces, was modelled or sculpted with considerable imagination, virtuosity and technical competence ... the techniques of making pottery, in many ways, haven't changed for centuries."
Mr Barr is still thrilled with his $300 estate-sale purchase - "It's on my table, and I love it."
Moral of the story: Hold onto your school artworks!