Warren Buffettâs lunch auction to benefit a San Francisco charity has drawn a top offer of $1.51 million with four days of bidding remaining, putting the annual fundraiser ahead of last yearâs pace. The weeklong auction on EBay Inc., which began yesterday, has generated at least four bids of more than $1 million, according to the website. Last year, bidding reached $400,100 on the third day and set a record of $2.63 million in the final hours. This yearâs auction closes June 10.