Tom Brady's "last" touchdown ball is purchased by a fan for $518 628. Brady then unretires

A fan paid over half a million dollars to purchase the last NFL football Tom Brady threw before he retired last season. 

Tom Brady's "last" touchdown ball is purchased by a fan for $518 628. Brady then unretires

Experts said that the ball is now worth less than it was before the 44-year old athlete announced Sunday that he would be returning to pro football.

New Jersey auction house Lelands sold the football on Saturday for $518,628. The high price was due to the belief that the football was used for the final touchdown pass by one of the most successful quarterbacks in NFL history. Just 24 hours after the auction was closed, Brady declared via twitter that he would be returning to the NFL. This marked a difficult break for the winning bidder.

David Kohler, a sports memorabilia expert, stated that the ball's current value is "a lot less" and added that once Brady throws another touchdown, then the ball's worth will "be a fraction" of its original value.

It is not clear if the winner of the auction intended to keep the football, or sell it at a later date. Lelands declined to identify who the winner bidder was.

CBS Sports host Adam Zucker said that he hates to be the man who paid $500,000 for Tom Brady’s last touchdown pass.

Brady is the only history-making quarterback to have won a championship with two different NFL teams. Over a period of 22 seasons, he has been a part of seven NFL championships. Brady has also thrown the most touchdown passes in league history, and has been named Super Bowl MVP five times.

Brady used the auctioned football in Tampa, Florida on January 23 to throw a 55-yard touchdown to Mike Evans, his teammate, during a playoff match against the Los Angeles Rams. Evans scored and threw Evans' ball into the stands at Raymond James Stadium. The ball was caught by a spectator and he decided to sell it.

"If Evans hadn't tossed it into a stand, it would still belong to the Buccaneers. It would never be offered publicly," Lelands wrote on its listing.

Brady's sports memorabilia is known for high selling prices. An example of this is the autographed rookie card that Brady sold last July at an auction where it was valued at $3.1 million . Last May, the football he used to score his first touchdown of his career was sold for more $400,000