Gwyneth Paltrow may command about $10 million a film, but you can lunch and shop with her and Calvin Klein on Madison Avenue for just $13,500.

At a recent benefit for Christopher Reeve's paralysis foundation, a deep-pocketed fan splurged for Gwyneth without suffering any guilt. Another bidder scored a Knicks game with Billy Crystal for just $10,000.

Last month, a managing director at Lehman Brothers spent $2,000 to deliver meals in the City Harvest truck with Susan Sarandon and an accessories honcho bought a film screening with Sigourney Weaver for $5,500.

While the shaky economy pinches pockets, stars for sale are keeping New York's most established charities afloat. Rather than cut a check for charity, celebs are peddling themselves to philanthropic fans who are more likely to cough up big bucks for stargazing than say, getting their name on a plaque.

At an upcoming benefit for Seeds of Peace, you can bid on the privilege of having Kim Cattrall babysit your kids. Fiamma chef Michael White, meanwhile, will cook dinner for 12 at your home to benefit ovarian cancer research. "It's easier to get a service donated than a check, especially in a tougher financial climate," says philanthropist Muffy Potter Aston.

While getting high bids can pad a celeb's ego, going on the block has risks.

Last May, a date with Candace Bushnell of Sex and the City fame fetched only $300 at a Housing Works benefit for homeless AIDS patients. And, a few weeks ago, naughty actress Bijou Phillips offered herself up for auction at a Safe Space benefit -- but the organization declined.

Auction anxiety can also plague celebs, who try not to take their "value" too seriously.

"It's definitely a challenge to try not to take a low bid personally as well as not thinking a high bid is anything more than a reflection of the level of wealth and sobriety in a room" says a celebrity who requested anonymity but has been auctioned off for more than $15,000 on numerous occasions. "But my obligation is to the charity, not my ego."

For tennis ace John McEnroe - who recently sold a tennis lesson for $23,000 to restaurateur Jeffrey Chodorow - being auctioned is often more rewarding than just donating cash. "Giving services and time can often be more meaningful than writing a check," says his manager, Gary Swain.

"He likes to do it to keep fit, and it's something he's told by charities that they value as being able to generate a lot of money."

And sometimes, celebrities themselves are the ones doing the bidding. At a recent AmFAR benefit, Miramax mogul Harvey Weinstein paid $100,000 for Elton John to perform a song.

"When high-profile personalities use the value of their celebrity in an auction situation, the audience always responds positively," says Bennah Serafaty, director of publicity for AmFAR.

Bidding on celebrity goods adds an element of sport to otherwise dull fund-raising events. On Monday night at a benefit for the Moth, a hip storytelling club, writer Alex Roy, 30, won a bidding war by spending $4,600 to fly over New York in a private plane piloted by director Doug Liman (Swingers, The Bourne Identity).

"There are several members of the Moth community who are constantly trying to upstage each other by bidding on these things," says Roy.

"This is an excuse to give them money and get a laugh out of it."

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