The investor's favorite stocks are selling cheaply right now.

Lunch with Warren Buffett is up for sale on eBay again. The Oracle of Omaha will break bread in New York with the winning bidder and seven pals, with proceeds going to the Glide Foundation, a San Francisco charity.

With a few days to go, bidding has reached $81,000. Last year the winner, a Chinese fund manager, paid $2.1 million.

But you don't need an expensive New York lunch with Mr. Buffett to invest alongside him these days. Despite this spring's stock market rally, several of Mr. Buffett's favorite stocks are selling for less than he paid for them.

Mr. Buffett liked oil giant ConocoPhillips (NYSE:COP) enough to invest $7 billion in the stock through the end of last year, at an average price of $82.55, according to the Berkshire Hathaway annual report. Anyone buying today can get it for about $41.

Mr. Buffett has conceded an "unforced error" in buying this oil stock when oil prices were booming. But that doesn't mean he has given up on it. In his last comments on the subject a few months ago, he reiterated his belief that demand for energy would remain strong. At current prices ConocoPhillips is about 13 times this year's forecast earnings, but analysts predict that will drop to a cheap 7 times in 2010