Based on the old catalog - the coin had $38 dollars worth of gold in it when the catalog gave a value of $150 in good. Today the metal value is closer to $97. Therefore, it had a premium of about $100 OVER gold content when the catalog was created. So it is a VERY good deal at spot - even mounted. When prices adjust to reflect new metal values it should rise to about $200.
Now the only thing to make sure of is that the coin is real. The standard weight of a ducat is 0.11 grams. These were trade coins and at the time they were well received worldwide so the weight should be accurate. The alloy was 0.986 fine gold - so an SG should be very high like 18.9.
The coin is VERY soft.