"very good excellent shape original?" very subjective.....
REALLY GOOD rear fenders unbroken could be $150-300 each; fronts $300-500 each.
More depending on rust, previous work, shape, dents etc etc.
Then there's early take off and NOS which are ridiculous for 31's
That's like asking what is the value of a 2-bedroom ranch house. Too many variables. If your buying them then you know the value. If your selling them ask the locals what they may worth. Condition is everything.
31 rear fenders for a sedan with the dimple are getting harder to find and a nice set with uncracked beads can fetch $600-750 a pair. A nice set of fronts without an bead breaks can go to $800-1000. I should think as well it depends on the seller and his/her motivations. There are always bargains out there. Have someone plow into your A and see what the insurance company is willing to pay to have it restored back to original. I had a friend who was plowed into the rear of his 29 sedan and he offered me $750 for a nice used rear sedan fender(very common fender). I think some of his offer was vindictive against the other driver but the insurance company didn't blink an eye.
I have fenders in stock that I paid $20-50 for but have had them for 20-40 years and surely would not part with them for anywhere close to that price.
So my thoughts are a nice set of fronts and dimpled rears with minimal repair needed should be in the $1500 and up range as fair value.