I would suggest $10-$15K for a decent correctly restored driver. Much more if it's a 100 point restoration. The prices of these cars is not what they used to be. Here's a start.
https://www.nadaguides.com/Cars/1940...r-Sedan/Values
Take someone with you who "knows" 1940 Fords. For example, here's one that you should not consider unless you want to dump a ton of money in for a correct restoration.
https://www.hemmings.com/classifieds...e/2162240.html
Notice: This car has not been restored correctly. Needs a total restoration.
It's a mess. No heater and many missing parts. Wrong interior. The ad is very "puffy" and misleading to an unsuspecting buyer looking for an original car.
Not worth anywhere near the asking price. You are better off buying one already restored correctly with good paint, chrome, interior, engine and drive train unless you desire a project.
Make sure your car has a matching numbers title, also. Provenance would be assuring.
I am sure there are other Fordbarn 40 Ford owners who can offer excellent opinions.