(CNN) -- For the 300 fans who are accompanying talk show host Oprah Winfrey on what is being billed as the Ultimate Australian Adventure, the trip is a unique opportunity to take in the sights and wonders of the country with the TV icon.
But for Australia -- a country that heavily relies on tourism -- the investment is expected to pay off manifold in publicity, the government said Monday.
The eight-day trip began last week and ends with two taped shows at the Sydney Opera House, which has been renamed Oprah House.
Footing the bill for Oprah and her guests will collectively cost the government AUS $5 million, said Andrew McEvoy, managing director of Tourism Australia.
But the value equivalent in exposure has already made it a smart investment, he said.
"Just before Oprah turned up into our country, the number was $38 million," McEvoy said Monday. "So that was three or four days ago. I can imagine that to double in the time that she's been here. And I can imagine that to treble."
He said the number could further skyrocket next year if Oprah commits to making "at least four hours of Oprah Winfrey television, which will go to 145 countries around the world."
Oprah and her group have visited the Great Barrier Reef, gone on a wine-tasting excursion to Hunter Valley, taken in a scenic flight over the Australian outback, partied in the Royal Botanic Gardens and trekked up the Sydney Harbour Bridge, which adorned with a big 'O' in her honor.
"I can't believe the energy of Oprah herself, her crew -- they're phenomenal," McEvoy said, adding "everyone is full of adrenaline."
During the media mogul's career, many have cashed in on the "Oprah effect," which has launched sales of what she promotes.
Oprah is in the midst of her farewell season of her show. Earlier this year, she showed her gratitude to her audience by announcing the all-expenses paid excursion.
Journalist Tracey Holmes contributed to this report.