While the targets feature a faceless figure, there are a hoodie, Skittles and what looks like a can of iced tea. Cross-hairs are aimed at the chest, WKMG-TV, Orlando, Fla., reported Friday.
Martin was wearing a hoodie and had purchased both iced tea and Skittles minutes before he was fatally shot in Sanford, Fla., by neighborhood watch volunteer George Zimmerman in February, police have said.
Zimmerman has pleaded not guilty to second-degree murder charges, claiming he shot the unarmed 17-year-old in self-defense.
The ad, posted on a firearms auction Web site, said the seller, whose identity was unknown, supports Zimmerman and believes "he is innocent and that he shot a thug."
In an e-mail, the unidentified seller told WKMG-TV, "My main motivation was to make money off the controversy."
"The response is overwhelming. I sold out in two days," the seller said, not specifying how many targets were sold. He said most of them were purchased by two Florida gun dealers.
Zimmerman's attorney, Mark O'Mara, said he fears the targets will further inflame tensions.
"It's this type of hatred -- that's what this is, it's hate-mongering -- that's going to make it more difficult to try this case," said O'Mara.
Lawyers representing Martin's family have not commented on the targets.