In 2015 the U.S. Mint had trouble obtaining platinum coin planchets, which resulted in only one platinum coin being issued that year – the $100, 1 oz Proof with an attractive neo-classical design by Joel Iskowitz called “Liberty Nurture Freedom”. It was the first of a two-coin set with the 2016 issue, which has a much higher mintage.
The 2015 coin sold out in minutes, and the final audited mintage came in 3,881, the lowest for any platinum proof coin and one of the lowest modern coins overall. As a result, the value of the coin quickly rose, reaching as much as $4,000 for 70-graded pieces, which today can be obtained for $3,000 or a little less.
The coin is similar in some ways to the 1995 Proof silver eagle in that, while uncertain, it is unlikely the Mint will in the future release a platinum coin with as low a mintage. In fact, at the time the Mint received many complaints from buyers who were unable to get their order through in time.