When is a penny worth $300,000? -- When it’s one of the first copper coins struck at the U.S. Mint in Philadelphia, in 1793.

  • Rare US coins sell for pretty penny at auction in Florida
  • One of first copper pennies sold for $300K
  • $4 gold piece call 'Flowing Hair Stella' sold for $750K
  • Rare half-dollar minted in New Orleans in 1838 also sold 

The George Washington-era penny is one of about 500 in existence, according to Mark Borckardt, a senior numismatist with Heritage Auctions in Dallas, and it went up for auction this week at the annual Florida United Numismatists convention in Tampa.

The convention is one of the five largest coin and currency collectors’ shows in the nation, experts say.

Three historic coins, including the pricey penny, went up for auction Thursday evening. The auction drew $24.9 million in sales.

Other high-value U.S. coins sold at auction included a half-dollar minted in New Orleans in 1838. It was one of the first 20 produced there.

A $4 gold piece called a “Flowing Hair Stella,” sold for $750,000.

“It was an experimental piece that the government produced, hoping to create an international coinage,” Borckardt told the Associated Press. “It’s literally the forerunner of today’s Euro. The government finally decided no, that’s not going to work.”

There are only about 15 to 20 of those quarter-sized gold coins in existence.

The three coins sold at a high value due to their rarity and excellent condition.

“Collectors interested in these have a very strong sense of history, both American history and financial history,” said Borckardt. 

Information from the Associated Press was used in this report.