No figures available on '65 four door production. Maybe a guess would be 50,000 based on total Chevy II production in '65. All '65 trim is rare, so if it's gone it devalues the car.
Overall a '65 4 door is not a vary rare car, nor is it sought after in the collector market. No trim and needs a new engine....everything else better be above average for 5K JMO.