YES Network.com

Earlier this year, Karl Kissner found a rare lot of early-1900s baseball cards while cleaning out his aunt’s attic, a haul that likely belonged to his grandfather and was left untouched for nearly a century.

On Thursday, 37 of those cards were put up for auction during the National Sports Collectors Convention in Baltimore, and Kissner’s family found out exactly how much that three dozen was worth: $566,132.

The entire 700-card collection, which experts believe could fetch upwards of $3 million at auction, will be sold over the next couple years, with the 20 cousins of Kissner’s generation splitting the profits.

The first 37 included nearly an entire set of the rare “E98” Series, one that contains the liked of Hall of Famers Ty Cobb, Cy Young, and Honus Wagner, and they were expected to bring in somewhere around a half-million dollars. According to Chris Ivy, the director of sports auctions at Heritage Auctions, the cards were sold in three lots, with two going to Internet bidders and one going to a live bidder in Baltimore.

“It was a lot of fun," Ivy said. "The room was packed."

The lot containing the near-complete E98 set sold for $286,800, and a Honus Wagner card that was judged to be in perfect condition by Professional Sports Authenticator, went for $239,000.

“We're very excited that we can all share in this find,” said Karla Hench, one of Kissner’s cousins who helped find the cards. “It's like a gift from our grandfather to keep passing on."

Kissner himself said that beyond the financial windfall, the fact that the discovery brought the family together – 14 were scheduled to be at the Baltimore auction – was even better.

"It started out with a walk down memory lane, and this is going to create nothing but new memories," Kissner said. "This is a blessing that will grow throughout this family."