New Zealand 1/2 crown 1940 Centennial coin value

The image of this coin is simply an example of New Zealand 1/2 crown 1940 Centennial type coinage.
Cost approximate and valid for common coin only (without rare varieties).
I do not buy or sell coins - this is just a catalog.

Governor - George VI king of Great Britain (1936-1952)

Currency - Crown= 2 1/2 Florin=5 shillings=62 pence=248 farthings
Type - commemorative coin

Composition - silver 0.500
Diameter - 32.0 mm.
Weight - 14.14 g.

Years of coinage - 1940

Reverse:
Radiant sun above city, standing figure in foreground
Legend: NEW ZEALAND CENTENIAL HALL CROWN / 1840-1940

Obverse:
King's head left
Legend: GEORGE VI KING EMPEROR

Edge: Reeded

Krause catalog number - KM#14

Coins price in "UNC" - 20-30 USD