What is the value of a 20 dollar gold liberty coin 1873 S mint mark?

The 1873-S Liberty Head double eagle has two varieties, a Open 3 and a Close 3. This assessment is for the most common Close 3. For an accurate assessment of value the coin needs to be seen and graded. Assuming the coin is circulated, most coins show a lot of wear. In general retail values for low grade coins are $1,700.00-$1,740.00, better grade are $1,790.00-$1,800.00 and coins showing almost no wear run from $1,830.00-$2,000.00. Values are a market average and only for coins in collectible condition, coins that are bent, corroded, scratched, used as jewelery or have been cleaned have far less value if any to a collector or dealer. The Melt Value as of 11-19-10 is $1,309.90