Original videotapes of the Apollo 11 moon landing which a NASA intern bought for $217.77 (£174.14) were sold for $1.82 million at a Sotheby's auction in New York on Saturday.
They were bought by Gary George at a government surplus auction in 1976.
Lasting two hours and 24 minutes, the tapes are far sharper than those seen around the world at the time of the moon landing on July 20 1969.
The footage broadcast across the globe lost quality by the time they were seen on television sets, because of being transmitted via microwave towers,
These tapes remained in-house. They represent the "earliest, sharpest, and most accurate surviving video images of man's first steps on the moon," Sotheby's said.
They show the entire moonwalk as it was seen by Mission Control staff in Houston, as well as Neil Armstrong's phone call with US president Richard Nixon.
The tapes were recorded on a Westinghouse camera NASA had commissioned to send the footage back to earth.
Placed in a shock-proof insulated mount, the camera captured Armstrong's descent onto the lunar surface, before being placed on a tripod.
Mr George was an engineering student at Lamar University in Texas as well as an intern at the NASA Johnson Space Centre in Houston.
He bought around 1,500 reels of magnetic tape and gave most away, apart from three which his father noticed were labelled "APOLLO 11 EVA | July 20, 1969 REEL 1.
Mr George gave the reels little attention until 2008 when he heard that NASA was trying to locate the original tapes.
The purchaser of the tapes was not disclosed by Sotheby's.