I always ask what price would buy it. If they say it's not for sale, I say you'd sell it for a grand so there's got to be a number between 1 and 1,000 that will buy it. Then after they throw out a number I come back with it MIGHT be worth that IF it was in MINT condition. Then I ruthlessly nitpick the bike down to a scratch, scuffed bolt, wrong part, non original tires, pedal grip and seat wear, and mention the MONEY I'm going to have to dump into it to make everything absolutely perfect. That has a tendency to shake them. Then I make a fair offer that is 2/3 what I think it is worth.