So Walton put in a bid that far exceeded the amount offered by other potential buyers.
Walton, of Knoxville, Tenn., will pay $262,000 for the card, which was auctioned off this week by the Baltimore-based School Sisters of Notre Dame. Proceeds from the sale will benefit the order's ministries for the poor in 35 countries.
The price exceeded the expectations of auctioneers at Dallas-based Heritage Auction Galleries, who had predicted it would fetch between $150,000 and $200,000.
Walton, 35, who owns seven sports card stores in the Southeast, said the story behind the card motivated him to make a generous offer.
"To be honest with you, we probably paid a little bit more than we should have," he said Friday. "But with the back story, and the fact that it's going to a really good charity, to us it just seemed worth it."
The Wagner card, produced as part of the T206 series between 1909 and 1911, is the most sought-after baseball card in history. About 60 are known to exist. One in near-perfect condition sold in 2007 for $2.8 million, the highest price ever for a baseball card.
A shortstop nicknamed "The Flying Dutchman," Wagner played for 21 seasons, 18 of them with the Pittsburgh Pirates. He compiled a .328 career batting average and was one of the five original inductees into baseball's Hall of Fame.
The School Sisters of Notre Dame inherited their card from the brother of a deceased nun after he died earlier this year. The card had been in the man's possession since 1936 and was unknown to the sports memorabilia marketplace.
Although the card is in poor condition, that didn't deter Walton. He said the high bid was $180,000 when he put in his first and only bid Thursday afternoon -- for $225,000. The final sale price ended up at $220,000, plus a $42,000 buyer's premium.
Walton said he bought it to honor his uncle, from whom he inherited the chain of card stores. Christopher Walton, who died in 2004, claimed to have owned a T206 Wagner card in the 1930s.
"He doesn't know what happened to it, and it was his dream to get another one of those cards back -- in any condition," Walton said. "I feel like me acquiring this card is continuing his legacy. ... He referred to it as the Mona Lisa. He was so sad about it."
Sister Virginia Muller, the former treasurer of the order who was entrusted with the card, said in a statement that she was thankful for the support she has received since word spread that the order was selling it.
"We may not have known who Honus Wagner was before this, but his name is blessed to us now," she said. "Now we're ready to go back to doing our work."