Warren Buffett auctions off a lunch at Smith & Wollensky each year at his charity event. AP Warren Buffett has been auctioning off a "power lunch" since 2000 at his charity event for GLIDE Foundation, an organization dedicated to reducing poverty and marginalization.

The highest bidder gets to bring up to seven people to dine with the steak-loving business magnate at Smith & Wollensky steakhouse in Manhattan.

In 2007, Mohnish Pabrai, managing partner of Pabrai Investments, and Guy Spier, author of "The Education of a Value Investor" and manager of Aquamarine Capital, forked out $650,000 amongst the two of them to dine with Buffett.

"Lunch with Buffett, we figured, would be a good way to give to charity, but it would also be the ultimate capitalist master class — a chance to see up close what makes the Sage of Omaha tick and to learn from his wisdom," Spier reflected in an article published in Time.

It was worth every penny, Spier concluded, and not in the way that most people would think; rather than picking Buffett's brain for investing tips, Spier used the lunch as an opportunity for personal growth and to learn how his mentor approaches life.

"Meeting with him one-on-one really enabled me to absorb and internalize some of the the ways in which he is in the world," he said in interview with Opalesque TV.

After meeting Buffett, Spier changed his life in two big ways: First his social circle, and then his location.

"The lunch made me realize that I had previously undervalued the power of making sure that I am around people who are better than me, and around whom I can improve," he wrote in an article for MarketWatch.

Since the lunch, he has focused on surrounding himself with "givers" rather than "takers," which he reflected on in episode 14 of "The Investors Podcast." He said:

As I distanced myself from some of these takers, I started noticing some of the givers that were around that I just wasn't paying attention to. There were quiet wallflowers in the corner that I should have been paying attention to, because they're actually wonderful people who weren't trying to insinuate themselves in any way.

Another enlightening lunch lesson was learning the distinction between making decisions according to your "inner" and "outer" scorecard: Do you make decisions based on what you truly believe, or are you motivated by what others would think of you?

"Understanding that concept went right to the core of my own doubts and after that lunch, I was determined to listen more carefully to my inner scorecard," he reflected in his MarketWatch article. "It was this distinction that made me realize that I needed to leave New York and helped me decide to move to Zurich."

Within a year, Spier left Wall Street for Zurich, Switzerland.

While $650,000 seems like an outrageous price for a lunch, Spier says it was a steal.

The price tag on Buffett's "power lunch" has soared; a year after Spier dined with the legendary investor, lunch went for $2.1 million, and this year, it sold for a whopping $2.35 million to a Chinese businessman.

"We feel like we got an absolute bargain," he told Opalesque. "Especially considering that Warren Buffett showed up at Smith and Wollensky in New York with a huge amount of energy, completely engaged, and spent 3.5 hours with us, answering any and all questions that we had."