Want to have lunch with Warren Buffett? Expect to write a check for at least a couple million.

In less than a minute after it launched, bids for a lunch with the Berkshire Hathaway CEO reached $1 million. That figure is expected to rise as the auction, which opened Sunday night at 7:30 p.m. P.T, and ends on Friday at 7:30 p.m. P.T.

For the 18th year in a row, Buffett is auctioning off a meal with himself to benefit the GLIDE Foundation, a San Francisco-based charity that supports the homeless. To date, he's raised about $23.6 million. In past years, winners have paid more than $3 million to dine with Buffett at the Smith & Wollensky steak house in New York City. The winner is allowed to bring up to seven guests.

The bidding is highly competitive, as business professionals from as far as China have shelled out millions for the chance to hopefully land a lucrative deal with the billionaire. Former fund manager Ted Weschler is the only person who went on to work with Buffett, after winning two consecutive auctions that cost him $5.3 million, according to CNN Money.

Other auction winners include Singaporean businessman Andy Chua, who paid $2.2 million in 2014, according to CNN Money. In 2015, the Chinese gaming company Da Lian Zeus Entertainment shelled out $2.35 million. Last year, Buffett's guest was an anonymous woman who spent $3.4 million, Fortune reported.