the grading landscape
Prior to the formation of PCGS in 1986 and NGC in 1987, a coin's stated grade could literally shift up or down every time that it changed hands, depending upon each new owner's interpretation and application of current grading standards.
However, since the market's general acceptance of certified grading, coin grades are now somewhat locked in. Coins that are graded too conservatively are "cracked out" of their PCGS or NGC holders and resubmitted for a new opinion. Yet, the market may no longer correct a grade that is too liberal, and in a numismatic version of Gresham's Law, bad grades accumulate in the market, driving out good.
Additionally, grading standards have loosened considerably over the past twenty years, so that many coins that were once correctly graded under a tighter grading regime may now be proper candidates for a grade or two higher.
Furthermore, in October 2007, John Albanese along with another twenty or so dealer shareholders formed a new company, Certified Acceptance Corporation (CAC), in order to offer a second opinion on the correctness of the opinions rendered by PCGS and NGC. Then, in March 2010 PCGS announced the implementation of "plus" grading whereby they would split the grades from XF45 through MS68 and PR68, using a "+" suffix for each coin that fell within the upper third of each grade range. NGC followed shortly thereafter with plus grades of their own, in addition to NGC's existing use of "star" grades for coins with exceptional eye appeal.
Well, if this grading service treadmill seems too confusing, you're not alone. The grading "standard" for U.S. coins has clearly been fractured, some would argue broken, yet the presence of a plus sign, or a star, or a CAC sticker can mean an increase in value of thousands of dollars. Additionally, a coin certified by NGC can, in many cases, be worth substantially more if graded the same at PCGS.
And if that isn't enough, the practice of altering a coin's surface to simulate a higher grade in the hope of fooling one of the grading services is rampant. These "doctored" coins have accumulated in both PCGS and NGC holders, and some of the most deceptive ones have even passed muster at CAC. Unfortunately, the overwhelming majority of new collections that I come in contact with include doctored coins, including those collections built with the assistance of self-described "picky" dealers.
a second opinion
For both new and existing clients of O'Connor Numismatics, we offer to review your collection in order to identify those coins which may benefit from recertification, and those that may present problems when the time comes to sell. For existing clients, we offer this service at no charge as part of our regular review process. For new clients, we will discuss any cost on a case-by-case basis.