He's probably been talking to his buddy.

Tell him no thanks and let it sit for a while.
Odds are, he'll be calling you back.

$400. strikes me as a more than fair price for the car.

Around here, only the drag race gang wants Monza's and there ain't too many drag racers to start with.

(Be sure it comes with a steering box. If you don't use it you can sell it to a street rodder and get some of your $$ back.)