Whats is worth 8 3/4 with suregrip, drum to drum, 3.91's

My thoughts is that this rear end would live forever is someones 400-500 HP car...
So I should pass it on while
1. its in great working order
2. it has value to myself as a seller, and to the future buyer

I need to start pricing out what Im going to have in a 9 inch, and go from there.

thanks all, seems I have my ballpark numbers.