how much should i offer?

need help. i have a chance at a 72 duster. original owners son has it. original 340 car,auto, orange with vinyl top, usual rust and fading, parked 8 years ago,supposedly ran last year. how much should i offer without hurting his feelings or scaring him off. hes hesitant about selling but i think he knows he will never get it going himself, i was thinking 3000? what does everyone think?