What is a rare date for nickels?

There are only a few truly rare dates. Among standard issues, 1877 and 1909-S are considered to be key dates. 1877 Indian cents retail for about $1000 in worn condition and go up to $150,000 in top condition. A 1909-S retails for $500 to a several thousand.

There is also an 1888/1887 "overdate" resulting from re-use of an existing die. While this could technically be considered an error coin its value is anywhere from $2300 to $50,000