Australia hosted the 2003 World Cup
Australian rugby chief John O'Neill believes smaller countries are being priced out of the opportunity to host the Rugby World Cup.
The International Rugby Board (IRB) wants £100m and £120m respectively from the hosts of the 2015 and 2019 events.
"There are very few countries that could put their hands up for that sort of commitment," said O'Neill.
"I'm not sure these can be sustained over the long haul without reducing the candidates down to France and England."
England's Rugby Football Union has already held informal discussions with the Welsh Rugby Union about launching a joint bid for the 2015 competition.
Japan - who lost out to New Zealand for the right to host the 2011 edition, are also expected to bid again.
We have an interest in potentially bidding for 2019
O'Neill, in his second spell as Australian Rugby Union chief executive, presided over the successful 2003 World Cup in Australia.
"Australia has led the way in supporting major events in
cash and in kind," he added.
"But these £100m and £120m figures for 2015 and 2019 are at a level that we haven't seen before.
"It's almost saying it doesn't matter if the host doesn't
make a profit.
"You could end up with a situation where the Olympics were in 1984, when they couldn't get anyone to host the Olympics and Los Angeles stepped up and did so on their own terms."
Despite the price hike, O'Neill says the ARU is considering making a bid for the 2019 competition, with the IRB seeking expressions of interest by 15 August.
"Clearly, we have an interest in potentially bidding for 2019," O'Neill added.
"We'll go through an assessment process taking into consideration all the pros and cons of another tilt at hosting a World Cup."
The 2007 World Cup in France was the most successful in the tournament's 20-year history, with 2.25 million fans attending the matches, up to 4.2 billion watching worldwide on television, and an economic impact of £3.18bn in France, according to IRB figures.