See several Auction sites, Guns International prices will vary make an informed decision cause it is a .32 No One wants that caliber I`ll give ya $150. just to help you out YES folks do and they always will take advantage. I am teaching the Wife and Kids NOW how to look at several different sites when I pass.. (True Story) I walked into a Local Gun Store I had a Steyr M40 1 Gen in a Steyr Box with 3 12 round Magazines all paper work( I have like 3 of them) Guy behind the counter says $75 cause he is taking all the chances and He has never heard of this Steyr. Behind him on HIS wall hangs a Steyr Aug Bull Pup in .223/5.56 I closed the box said you got one hanging on the wall behind you and WALKED OUT I have NOT returned and will never return.
Your pistol is one of the last German made PPKs imported by Interarms before the 1968 Gun Control Act. Its a rather rare bird and some collectors, depending on their level of sanity, will pay North of $2000.00 for a pistol like yours.