It appears some people are keen to get their hands on it with one woman commenting: "I just asked if this was still available" — however, whether she was actually being serious or is to be debated as she signed off with several laughing emojis.
"I've had one before should of sold mine," another person joked.
One woman shared a screenshot of the alleged conversation she had with Matson asking if it was still available.
"You sure you didn't eat it," the (potential) bidder asked, to which Matson responded: "Like I said, it's available", adding that she still has the original box.
She told the Courier Mail her advert is legitimate, revealing she has been contacted by close to 100 people.
However, the highest bid so far sits at $4500, along with being offered "a half can of coke and some gummy worms as a trade".
Matson told the publication she's always up for a laugh, especially if it distracts people during lockdown.
She said she discovered the "rare" Shape while watching beach volleyball on the Olympics, before showing her husband and making a TikTok video.
She also said her asking price is based on what people were offering to pay.
And if you do want it, the 2-for-1 deal is preserved with care, sealed in a plastic container, with postage available and packaged in bubble wrap to ensure the biscuit "'is delivered conjoined".
While some may think it's completely outrageous, don't forget a Gold Coast teen was recently given $20,900 for her one-of-a-kind Dorito.
Within days, bidding for the chip had exploded to $20,900 and it later achieved bids of up to $104,000.
In fact, in a strange twist of fate, Matson told the Courier Mail her workmate is the sister of the lucky teen.