Well my friend the truth is the wreck of a bike, I would pay no more than $50-$100 period. I might even charge him to remove it. Another dirty trick that works if the bike is outside, is to strategically run an add looking for Old Honda's. Don't skimp, make sure it is an add that he might see. Now I don't mean go out and spend big money on it. Like $30, then call the city and complain about the eye sore of a bike.
I know dirty pool, but when it comes down to getting bikes cheap I NEVER play fair.
The other bike I would give him a good pounding and pay no more than $500 on a good day for it. After all you will need some cash left over to fix it. If you have to, wave crisp 100's at him as you walk away when he goes sour.
Really there are no rules for proper procurement of a vintage bike.
After all if the little old widow from down the street called you and wanted you to buy her deceased husbands semi-minty 40's Indian Scout that runs for $200 I would hope you would not stop and think through morales. At least not until it was in your name and in your driveway.
And remember that NO BIKE IS EVER AS GOOD AS IT APPEARS. When you get it home there WILL be suprises.
Junkie, what do you call the before? The Black Pearl?
That has come along ways.