A 1989 American Eagle 1-ounce gold $50 bullion coin graded Mint State
70 by Numismatic Guaranty Corp. sold for $22,550 at a Sept. 7, 2014, GreatCollections.com auction.
The coin is one of just eight similarly graded by NGC and the
auction firm noted that it was the first NGC MS-70 example of the date
to appear at auction. Nine bidders competed for the piece, which
opened on Aug. 20 with a bid of $1. NGC defines a Mint State or Proof
70 coin as having no post-production imperfections at 5x magnification.
This issue is usually encountered in MS-69 condition and
GreatCollections.com sold an example graded NGC MS-69 for $1,331 at a June 1 auction (for reference gold
was hovering around the $1,250 an ounce level at that time as was on
Professional Coin Grading Service has graded nine examples of this
Typically, for a coin to achieve a substantial premium for a
"perfect" MS-70 grade, it needs to be certified by a major
third-party grading service.