UNITED STATES: AR 50 cents, 1891, PCGS graded Proof 63, Seated Liberty type, lovely golden blue toning! R. Although 1891 was the final year of issue for the Seated Liberty design, the Philadelphia Mint only struck 600 proofs for collectors. While that might have been enough at the time, today there is a large demand for this date in particular which is much higher than the number of coins available.
Estimate: USD 800 - 1000