Coin for coin, there may be not be a greater challenge in any grade from the past century than the Barber quarter. In fairness, the Barber quarter did begin back in 1892, but the bulk of the dates in a Barber quarter collection and the two keys in most grades, the 1901-S and 1913-S, were products of the 20th century.
The question as to why Barber quarters are so challenging as a set has many answers. Logically there are some Barber quarters that had very low mintages. In fact, the 1913-S at 40,000 is the lowest mintage regular date silver coin of the past century. That alone is impressive and is a good indication that Barber quarters are not going to be...
Full Article: Big Three dates dominate Barber quarters - Numismatic News
