That's an extremely broad question because nickels have been minted since 1866 at 3 different mints. Please see the Related Links for value guides.
Also remember that except for the famous "war nickels" of 1942-45, US nickels have never been made out of silver so they're the only nickels that have any extra melt value. All other nickels are made of a copper-nickel alloy so any extra value they might have would be purely as collectible items.
1964 US nickels were minted at Philadelphia (no mint mark at that time) and Denver ("D")
Only the "War Nickels" of 1942 to 1945 were made with a silver content of 35%
Nickels that year weren't made of silver. There was no change in metal composition in nickels in the 1960s. The only nickels that do contain silver are those minted between 1942 and '45. Anything post-war is only worth face value.
5 cents. The only nickels to contain silver are the "war nickels" produced from 1943-1945 with a large mintmark over the Monticello. 1964 nickels use the same composition as today, have a high mintage and are easily found in pocket change. They are worth no more than 5 cents. There were over 2 billion nickels minted that year.
Several billion were made. This is a very common date with no added value in circulated condition. A nice uncirculated one may be worth about 25 cents. Billions of nickels were minted in 1964 as a stopgap effort to substitute for higher-denomination silver coins that were being removed from circulation for melting. They show up in circulation more than almost any other date.
1964 US nickels were minted at Philadelphia (no mint mark at that time) and Denver ("D")
Same as post-1964 nickels: NONE. The only exception is for nickels minted 1942-45.
Only the "War Nickels" of 1942 to 1945 were made with a silver content of 35%
Nickels that year weren't made of silver. There was no change in metal composition in nickels in the 1960s. The only nickels that do contain silver are those minted between 1942 and '45. Anything post-war is only worth face value.
5 cents. The only nickels to contain silver are the "war nickels" produced from 1943-1945 with a large mintmark over the Monticello. 1964 nickels use the same composition as today, have a high mintage and are easily found in pocket change. They are worth no more than 5 cents. There were over 2 billion nickels minted that year.
The last Australian Penny minted prior to the changeover to decimal currency was minted in 1964.
Nickels before 1964 are made of the same nickel/copper blend as nickels made after 1964. The only nickels to contain any silver are "war" nickels, minted 1942-1945. This means even buffalo nickels don't have any silver.
No mint mark means it was minted in Philadelphia, and a D indicates Denver.
1964 is one of the most common dates for Jefferson nickels, with more than 2 billion minted. Gold-plating doesn't add any collector value because it alters the coin.
The last Australian Penny was minted in 1964.
Several billion were made. This is a very common date with no added value in circulated condition. A nice uncirculated one may be worth about 25 cents. Billions of nickels were minted in 1964 as a stopgap effort to substitute for higher-denomination silver coins that were being removed from circulation for melting. They show up in circulation more than almost any other date.
The coins are still found in circulation and only face value.