The coin bought this weekend was a 1 cent copper coin minted in 1793, the first year the United States produced its own coins, the Orlando Sun Sentinel reported.
Nearly 600 coin and currency dealers packed the Orange Count Convention Center for the largest coin show in the country, said Cindy Wibker, the convention coordinator.
Wibker said more than 100,000 coin collectors were expected to attend the convention, which ended Sunday.
David Lisot, executive producer of Cointelevision.com, a news and video Web site, said there is a renewed interest in coin collecting.
"Everyone has that stash of old coins, grandma's stash, that was saved because no one ever throws away money," Lisot said. "But if you're interested in the value of what you have, you could go to a coin store, or to a convention like this, with hundreds of dealers available."