I know its a B body, but what's it worth??

My brother saw this advertised and I am going to look at it today. I have had 2 of these 71 Roadrunners in the past but with 340 4 speed pistol grips, same color. One of them I took my girlfreind, now my wife, to prom 40 years ago in.

1971 Roadrunner, 383, auto on the column, all original down to the pie pan and spare tire, #'s matching, 77,*** miles.