What is the estimated value of a Benjamin Model 3600-177 cal air rifle?

What is the estimated condition of the Benjamin model 3600. The current condition determines the value. Is it in Poor, Fair, Good, Very good or Excellent condition.

Without more information it is not possible to answer you.

The rifle was made between 1958 to 1964 and is a .175 caliber BB rifle not a .177 caliber bb rifle.