Washington (CNN) -- Like Dr. Evil learned in the Austin Powers movies, a billion dollars isn't quite what it used to be.
This weekend's G8 and G-20 summits are expected to top $1 billion in costs. At such a large price tag, it's reasonable to ask if the meetings are worth it. But according to former top White House aides, even with the hefty price the meetings more than pay for themselves in both tangible and intangible ways.
According to David Gergen, who worked for five presidents and has participated in several of these summits, the world has already seen a return on the current $1 billion investment.
"The G-20 meeting is expensive, but it has already paid for itself because China announced a strengthening of its currency, which is good for the United States and for many other countries," Gergen said. "China only announced it was going to revalue its currency upward because the G-20 was going to occur."
The summits also offer an opportunity for leaders to meet face to face, giving them a chance to build relationships and sometimes change first impressions.
"President Reagan's first G8 was in Canada, and at that time he was sort of seen as a cowboy by much of the world," Gergen recounted.
After that first summit, Gergen said, Ronald Reagan's image changed, "President Reagan had gained much more respect from other heads of state, but as well as from the public around the world." He added that Reagan even changed the perception of the international press who covered the meeting.
Giving a behind-the-scenes peek, Gergen described past G8s as opportunities to build coalitions and relationships. Reagan initially didn't like the idea of big international meetings, but he eventually found the G8 to be "enormously constructive," Gergen said.
The one-on-one sessions with world leaders were helpful in getting "across the United States' point of view and bringing along allies," Gergen said.
Former George W. Bush international economic advisor Dan Price has similar sentiments, pointing out that discussions at these summits aren't limited to the larger and more formal group settings. There are opportunities for informal talks, too.
"Discussions continue in the corridors, there are bilaterals, discussions continue over meals -- you achieve a sense of understanding," Price said.
And in times of crisis like in the fall of 2008, when the world economies were faltering, Price said, a global meeting of this magnitude can help build confidence. It was one of the reasons Bush wanted to elevate the G20 from a meeting that historically included only financial heads to a meeting with heads of state.
"It's a very significant gathering," Price said. "The G-20 nations control over 85 percent of the world GDP, so what they discuss and what they decide has an important impact on the global economy, and they're not meeting for a photo op," Price said.
With the G-20 focusing more on macro-economic needs, the G8 has shifted its focus to development needs. Price pointed out that over the past five to seven years the G8 has done enormous work in areas such as HIV/AIDS, malaria, tuberculosis, clean drinking water, and neglected tropical disease.
But Price said there's another reason for the meeting, and that's simply to foster a cooperative spirit.
"You also get a very palpable sense that it is a global community, and that one must act together rather than relapsing into unilateralism," he said.
With a billion-dollar price tag, getting to know your neighbors has become a very expensive endeavor.