Eric Holler, owner of SerialKillersInk.net, told WESH-TV in Orlando, Fla., the clothes and purses were originally purchased at a garage sale run by Anthony's parents. He said the buyer, Christina Werner of Mount Dora, Fla., wanted to "wash her hands of the situation" and sold them to him.
Holler, who is offering the items at $800 each, would not tell WESH how much he paid for them.
"Of course I'm trying to profit, I'm running a business here," he said. "I'm not in the business of losing money."
Anthony has kept a low profile since she was released from jail in 2011. She was acquitted that summer of murder but found guilty of giving false information to law enforcement about the disappearance of her daughter, Caylee, who was weeks away from her third birthday when she vanished.
After giving a number of other stories to police, Anthony eventually said the toddler drowned accidentally in her parents' swimming pool and her father, who has never been charged, convinced her to cover up the death.
"Casey Anthony is here! Own items from the infamous Anthony garage sale," Holler's website said.