not completely up on value of Impala muncie 4spd shifters, but I would imagine using one would kinda feel like stirring a 55 gallon drum of cantalopes with a drive shaft.
try to swap it for a Hurst!
I have had the original muncie shifter for my 65 Chevelle "restored" and I still can't stand it.
(It's on a shelf in the garage)
I'm sorry, you asked for the value, not an opinion. I know for sure it's rare and worth a lot more than a chevelle shifter as stated above.