"Over that 10-year period the Australian people, through their taxes, will provide more than $100 billion to veterans and this is $500 million for the commemorative side."
Pressed on why the project was expected to cost so much, Mr Chester said the excavation works needed to take place without damaging the Canberra building's facade.
"Why does anything cost a lot of money when it comes to construction jobs?" he said.
The federal government this week announced a discount card for returned service men and women, along with a jobs program to connect veterans with suitable employers.
Virgin Australia will also offer military veterans priority boarding and acknowledge their service during in-flight announcements.
Defence Industry Minister Steve Ciobo said it was "tremendous" for the airline to salute the service of soldiers.
"If we can get though not just airlines, but if we can do this across the board, I think that is part of reinforcing respect in the Australian community for these men and women," Mr Ciobo told Sky News.
"I want to congratulate Virgin for, in many respects, being a trailblazer."
Mr Chester also welcomed the announcement, but acknowledged many veterans would sooner embrace discounted airfares.
""Australians, by nature, tend to keep their light under a bushel. Some would be happy to get on the plane without anyone knowing they are there," he said.