It was made in 1975. (Today Crosman owns Sheridan.) See the link below and then scroll down to "Sheridan"
I must know the Condition of the rifle to give a more accurate value. But the values fall between $50 in poor condition to $235 in like new condition. Without a scratch on it and no wear.
It was made sometime between 1965 -1974
Here is the link to all of the manuals for Sheridan and Benjamin. Crosman owns Sheridan and BenjaminSee the link below.
1825 days