One industry body claims that some Economy Class tickets from London and Sydney may be the most expensive ever.Australian Aviation's analysis revealed that a trip to Sydney on the day of the reduction in cap was selling for more than $43,000 (USD 32,000). This 44-hour journey consisted of flying to Moldova, then connecting via Abu Dhabi to fly with Etihad Airways to Sydney.Photo credit: photoholgic via UnsplashThis is the most expensive flight found, but the analysis showed that similar routes were frequently more expensive than $30,000. The cost of a one-way ticket to Sydney from Paris was $30,000; fares from New York were $20,000, and tickets from Tokyo were $15,000.Australia's federal government announced last week plans to reduce the weekly passenger limit from 6,070 to 3,035 passengers in the near future. This is due to concerns that Australia's hotel quarantine system cannot cope with the highly infectious Delta variant.An estimated 35,000 Australians are still waiting to return home. However, travel industry groups claim that some airlines may have to stop flying to Australia because they cannot afford to carry as many passengers.Barry Abrams is the executive director of Board of Airline Representatives of Australia. He denied that any airlines that continued to fly to Australia during the pandemic were price gouging and called such allegations insulting.Abrams stated to the Guardian that it will be difficult for many airlines to keep their flights to Australia regular.Many people will ask whether it is better to run cargo flights than suspend passenger flights. It wouldn't be cutting off Australia, but I would expect reduced connectivity and availability for flights from Australia.