I was recently looking for a gold peice issued by the Polish mint in 1977 (?), which Krause puts at $150. I was slightly alarmed when I saw it at €400...has the gold price gone up that far ? I haven't found it with any other dealers.
Actually, that means the price has gone down in real terms. In 1977 the average price of gold was $147.68, so the coin was cataloged at almost exactly the bullion value of one ounce of gold. The current price of gold is ~€ 633 so the coin is being offered at the equivalent of less than two-thirds that same bullion value.
