This gun should be between $600 to $1000 dollars.
What is the value of a Walther Model II .22 cal. 9 shot magazine?
Walther, Beretta, Browning. Kel-Tech, NAA
Browning, Colt, Ruger, Smith and Wesson, Walther, Hammerli
Value depends on EXACT model and condition, but a pistol such as the Beretta Model 21 may be worth $125-200.
Depending on EXACTLY what you have and its condition, the range could be from a few hundred to multiple thousands of USD.
My grandfather's pistol used in ww1
50 or so
$200
20-100
100-1000 USD depending on EXACTLY what you have, how it is marked and how your definition of "very good" translates in the world of folks who do firearms for a living.
20-60 or so
These retail for about $85 new.