70 Swinger Value?

About a mile From my house there Is a 70 Dart For sale it has been there for almost a year now He wanted 4000 for it then went to 3500 but no one seems to want it. What is a good price for the car? it is actually pretty solid besides the Rust I have pictures of the frame is Really good and Floors, It Runs and the interior besides the Front Seat is in really great shape. So what are your Guy's thoughts?