For Mark Northcutt, buying and selling sports cards is a lot like following the stock market.

For Mark Northcutt, buying and selling sports cards is a lot like following the stock market.

"Most people have coffee and doughnuts in the morning," Northcutt said. "I have coffee and eBay to check the prices."

Northcutt is the owner of Mark's Cards PLUS, which opened a few weeks at 4026 Broadway in Grove City's historic town center. It's open every day of the week.

"I sell high-end sports cards," he said. "You can't just go to Wal-Mart or K-Mart and get them."

The prices in Northcutt's store can range from $100 to thousands. Available items include autographed memorabilia; rookie cards; cards with pieces of shoe, jersey or wood; toys and more.

The cards include newer designs and players as well as classics. His "Holy Grail," Northcutt said, was a Tiger Woods rookie card that he sold for $8,000.

"I've always been lucky," he said.

When a player is doing well or is inducted into a hall of fame for example, the price of his or her merchandise, like the stock price of a successful company, tends to go up, Northcutt said.

"This isn't a kids' business any more," he said. "Everything in here is real and guaranteed by the factory."

Everything he sells, Northcutt said, comes with a serial number from the factory and other necessary forms of authentication.

It's not enough to just say the person signed the item, he added.

"eBay has helped and hurt," he said. "You don't have to worry about getting fake stuff from a dealer ... A lot of us know each other."

Northcutt has owned a number of shops over the years, including one in Grove City, which is where he grew up.

"Fifteen years ago, I was on Old Stringtown Road," he said. "I feel a lot more at peace here than at flea markets ... (The store) kind of goes in with the downtown."

Northcutt said he has been a sports dealer for 25 years, but he has been collecting all his life. He called himself the "old geezer" of the business.

"I never get tired of this," Northcutt said. "I've always enjoyed selling stuff ... Nobody's been in the business longer than me."