Talk about bad timing. When Mastro Auctions, the country’s largest auction house for rare, vintage sports memorabilia, decided to set the date of its recent auction for December 12-15, no one could have known that the Mitchell Report, listing 89 major league players accused of using performance-enhancing drugs, would be released smack in the middle.  

What was a seismic announcement for the sports world had aftershocks in the memorabilia market—immediately. At the auction, prices for the memorabilia from two of the players named in the report, Barry Bonds and Roger Clemens, were dramatically lower than had been expected.

Bonds, who became the all-time home-run leader last year, had been under suspicion for years and had been arraigned on perjury charges the week before the auction. So Mastro president and C.O.O. Doug Allen wasn’t entirely surprised when a game-used, signed bat from the 2001 season, in which Bonds broke the single-season home-run record, sold for $12,000—less than the owner had paid for it.  

“Previously we’ve sold bats like this for $20,000, one for close to $30,000,” he says. “I warned the owner that there was a risk of it going for $5,000 to $6,000. But some people are dumping their Bonds items because they just don’t want them in their collections anymore.”

Roger Clemens, who is currently embroiled in a he-said/he-said battle heading to a possible Congressional hearing, also brought in lower bids. “We had a game-used New York Yankees jersey from Roger Clemens from the 2000 World Series that sold for $3,586,” says Allen. “That’s a jersey that would have gone for $6,000 to $8,000.” The seven-time Cy Young Award-winning pitcher was, until the allegations surfaced, a shoo-in for the Hall of Fame.

Prior to the revelations, the memorabilia brought in top dollar: Comic-book entrepreneur Todd McFarlane, one of the most avid baseball-memorabilia collectors around, shelled out $3 million for the ball that Mark McGwire hit in 1998, setting a record with 70 home runs in a season, and $517,500 for Bonds’ 73rd-home-run ball, with which Bonds broke McGwire’s record, in 2001.

Collecting sports memorabilia has long been a favorite activity for fans, but in recent years, as major league baseball attendance has mushroomed, it has also become a very big business, now estimated at $1 billion a year. Sotheby’s landmark $4.5 million sports auction in 1991 gave sports collecting investment legitimacy, and now, with other auction houses and rare-memorabilia dealers searching out and selling a coveted Babe Ruth home-run bat or a Mickey Mantle or Lou Gehrig jersey, some investors even see it as a smart way to diversify a portfolio.

“People approach it now as you would buying a Picasso or a vintage car,” says Colorado-based Marshall Fogel, who in 1989 began amassing a now 10,000-plus-item collection that was featured in the book Smithsonian Baseball: Inside the World’s Finest Private Collections.

But collectibles from the current era are proving to have been risky investments, with all the suspicions and a much greater supply of merchandise (view slideshow). Collectors and dealers are still weighing the fallout. “I always get calls for Clemens memorabilia for Christmas,” says Pete Siegel, owner of the New York gallery Gotta Have It! “This year I didn’t get any for Clemens…or for Bonds. And I wouldn’t stockpile any of their items either.”

Mastro’s Allen notes that whatever happens to their reputations in the short term, Clemens and Bonds will still in the long run be regarded as two of the best players of their era, so if a collector can buy low and hang on to a piece, it may still be a good investment—pending the outcome of the investigations.

Given the uncertainty, though, serious investors and dealers are shunning the current era completely. “I always recommend pre-1980 material,” says Mike Heffner, president of Lelands auction house in South Dennis, Massachusetts, which, nonetheless, presided over the sale of Bonds’ 73rd-home-run ball. “There have never been accusations of players cheating and there are fewer pieces on the market,” Heffner explains.

Still, experts believe that there is hope for the current era, for records fans can trust and the memorabilia to go with them: Alex Rodriguez, who isn’t suspected of steroid involvement and is expected to surpass Bonds as the home-run king. When he does, they say, that could be a several-million-dollar ball.