The most expensive baseball card might not be the 1910 Honus Wagner, which sells for $30,000 or so. And it might not be the 1952 Topps Mickey Mantle, which can set you back as much as $6,000.

The 1985 Mark McGwire rookie card might wind up costing someone $250,000. That's the maximum fine for copyright infringement under federal law.

Bogus baseball cards are out there, and they're hard to spot. They cost they same as the real ones and they might look nearly the same.

Years ago, when people found that baseball cards might be valuable, unscrupulous people began to print phony cardboard gold.

"We are aware of some counterfeiting, and the company policy is to vigorously prosecute anyone who sells counterfeit cards," Topps spokesman Normal Liss said. "We do everything that we can to stop it."

Topps is looking into reports of some fake 1985 McGwire cards that began showing up recently in California. If the cheaters are caught, they're likely to lose more than their bubble gum.

"There are federal, state and local laws to protect copyrights," Liss said. "Infringement can be punishable by as much as a $250,000 fine and five years' imprisonment."

When McGwire appeared in the '85 set as a member of the U.S. Olympic team, his card was virtually worthless. On opening day in 1987, it was still valued at a quarter. Forty-nine home runs later, the card was up to $20.

With modern technology, it's possible to mass-produce passible reproductions of full-color baseball cards for as little as 6 cents each, so the profit margin is there for those who don't think twice about defrauding people.

Some notable fakes that have appeared in the last decade include Pete Rose's 1963 Topps rookie card, Don Mattingly's 1984 Donruss rookie card, Mike Schmidt's 1973 rookie card and now the McGwire. It is believed that the fake Mattingly cards were commissioned by a pre-teen in Florida and distributed by a network of youngsters. The bogus Rose cards originated in California.

"The parties reponsible for the counterfeit Rose card were caught and prosecuted by local authorities," Liss said.

The Mattingly and Schmidt cards are still around. Many of the fake Rose rookie cards remain in the hobby with the words "Counterfeit" and "Original Reprint" stamped on the back.

In a burst of humor last year at a card show in Chicago, Rose even autographed some of them, signing "The Real Pete Rose" on them. Those cards had been stamped on the back and could do no one any harm. But what about counterfeits that haven't been marked? How can one spot a fake?

"There are ways to tell the difference," Liss said. "The pictures may be fuzzy, the type may be muddy or the card stock might be different."

Check the copyright symbol to see if it's sharp. And handle a card before buying it. Plastic cases hide many flaws in genuine cards and make bogus cards virtually undetectable. Even if the card looks right, take it out of the case and compare it in weight and print sharpness with one of such a common player as J.C. Martin or Steve Trout of the same issue. You might be able to tell right away that something is wrong.