Perth man auctioning off the Hamdog patent to the highest bidder

Mark Murray, creator of the Hamdog, is auctioning off the patent to the highest bidder. Photo / Facebook

Got a spare $100 million?

You could purchase a van Gogh self portrait, buy out Apple co-founder Steve Wozniak's entire net worth, or nab the exclusive global rights to the Hamdog.

Its creator, Perth man Mark Murray, believes his cross between a hamburger and a hotdog could be worth $100 million.

Murray first pitched his idea on Channel 10s Shark Tank programme last year, after successfully securing a US design patent for the "combination hamburger hot dog bread bun" in 2009.

Conceived in 2004, the $8 Hamdog consists of a beef patty cut in half, with a frankfurt inserted in the middle. It's topped with lettuce, tomato, cheese, pickles and three sauces - American mustard, tomato sauce and mayonnaise.

Since the news was reported last week, Murray has been inundated with requests from potential investors wanting to purchase the patent.

"I turned down a $5 million offer from an Australian company just last week," Murray said, adding that he'd been quoted "silly figures" by his financial advisers.

"I've been told [the Hamdog] could sell for $100 million," he said. "America's burger market is worth $250 billion a year. If the Hamdog could grab even five per cent of that market, that's $12 billion a year in revenue. They're crazy numbers."

The cross between a hamburger and a hotdog.

He's been interviewed by more than 100 media outlets, received thousands of emails from "fans" and been the subject of a rant by US talk show host Jimmy Kimmel.

"A man in Australia somehow managed to come up with a hamburger hotdog hybrid before we did and that is just flat out unacceptable," Kimmel said.

"This country was built on hamburgers and hotdogs. The hamdog is something we should have invented here."

On Good Morning America, he was even hailed as a hero.

The extraordinary amount of interest in the Hamdog - and the potential for it to earn millions - is why Murray is now auctioning off his patent to the highest bidder. On Friday, the design patent will be auctioned online.

In Australia, the Hamdog is protected by an Australian Design Registration, but in the US it's protected by a full US design patent.

He sees America as the ideal market and says he's already had inquiries from fast food outlets wanting to purchase his idea.

"I would love to visit America, go to a football game and wander to the back of a stadium and grab a beer and a Hamdog," he said.

But intellectual property experts say the $100 million figure Murray quotes isn't realistic.

Queensland University of Technology's intellectual property and innovation law expert Professor Matthew Rimmer says the original patent isn't rock solid, as it's a design patent which has not been certified.

"They haven't got a full patent. There would be questions raised about its validity," Prof Rimmer said.

"Another company could challenge the validity of the design patent and claim that the idea wasn't original because it's a couple of basic shapes. It's just not original, that's why I'd be sceptical about claims to value," he said.

"I'd be a bit cautious before investing in the Hamdog. It might be worth nothing."