The 1893/2 10C was discovered by Walter Breen in February 1961, who noted the variety on both business strikes and Proofs. PCGS continues to recognize this variety, while others do not, nor is it listed in the Cherry-Pickers Guide.
The undertype appears to show the diagonal bar and the lower base of a 2 behind the 3. Some claim this is merely a repunched 3.
In terms of rarity, the "overdate" has the lowest population of any of the coins in the Barber series. It is scarce to rare in Mint State, with most examples appearing in MS64. A small group of PGGS MS65 and MS66 examples exist, with none finer.
The price record for this variety was set in 2006, when a PCGS MS66 example owned by Dr. Steven Duckor sold for $11,500.
Heritage 1/2004:5660 - David Lawrence Rare Coins, sold privately in 4/2008 - Eugene H. Gardner Collection - Heritage 10/2014:98303, $8,225