Ron Guth:
The first Three-Cent Nickels of 1873 utilized the same-sized date logotypes as in previous years. Unfortunately, the small date and the shape of the 3 made it appear, at a quick glance, to be an 8 . Mint officials noticed this discrepancy and changed the shape of the 3 by opening the loops so that it no longer looked like an 8. By doing so, they created two varieties for the year.
According to the PCGS Population Report, the certified population of the Open 3 variety is just over half that of the Closed 3, which is in line with their original mintages. Despite this difference, most price guides value them equally.
The finest examples certified by PCGS include over two dozen MS65's, with none finer.