Jaime Hernandez: The 1864-L Proof Indian Cent has the lowest mintage in the entire Indian cent series. The mintage is estimated to be somewhere between 20 - 30 examples struck. Regardless of the mintage, there are no more than 20 examples that have survived in all grades combined. Most examples that have survived exist in PR64 and PR65 condition, with the majority of them having red brown surfaces. However, any grade and color designation in this coin is desirable, as it is a very scarce coin.
Ron Guth: The 1864-L is the rarest of all the Proof Small Cents. Approximately 20 examples are known today. Three die pairs were used to strike 1864-L Proofs: two different obverse dies were paired with the same reverse die to strike Proofs in 1864. Later (circa 1871), a new obverse was combined with a Proof reverse die then in use to essentially create restrikes of this rarity. The rarest of the die pairs is unique, known only by a PCGS PR-64 Red examples that appeared in numerous auctions over the past decade (this piece set the record price of $138,000 for this date in 2002).