Detailed information about the coin 1 Dollar (James Buchanan), United States, with mintage, descriptions, metal, weight, size, value and other numismatic data. In ? US$ The value of numismatics is directly correlated to rarity, age and condition. of these coins were minted. Its mint year is Both the P James Buchanan dollar coin and D James Buchanan dollar coin are each worth around $3 in uncirculated condition with an MS 65 grade.