Without more information, the question can not be answered. For example, what do you mean by "clip lock"?
pawn shop, gun shop, gun show
Try gun stores or gun shops
you probably mean PPK or PPK/S which is a Walther hand gun in 22 cal, 32 cal or 380 cal.
you get what you pay for.
Gun shop, gun show, pawn shop, want ad
Properly called a magazine, they are available on line from gunpartscorp as Product No. 1106890 $38.50 plus shipping
Try online at Numrich Gun Parts
Blue Book of Gun Values.
Want ad, gun shop, gun show.
Try egunparts, pawn shops, gun shows, gun shops, estate and garage sales.
50 USD
Depends on who made it.