Depends. It looks like there is a lot of rust on it (hood, fender arch, rocker panel) and it could get expensive to repare. You need to check the shock tower for rust also. Figure body repair and painting to cost anywhere form $2500 to $5000 and you will have $5000 - $7500 in a car worth $4000 -$6000 assuming that nothing else is needed (highly unlikely). Because of the rust, offer him $1500 if everything else checks out.
GT