Impossible to give an accurate answer without a detailed description of ALL markings, condition, box, papers, finish, grips, grip material, barrel, sights, magazines, accessories, papers, serial number.
The value of any firearm is based on the exact make, model and condition. Your Walther self loading (selbstlade) pistol has some degree of collector's value, which will be driven by condition. You will need a hands-on appraisal. Take your pistol to a local gun shop or gun show. There were at least 4 different versions made, and values are typically several hundred dollars- again, based on model and condition.
Depending on EXACTLY what you have and its condition, the range could be from a few hundred to multiple thousands of USD.
Well, there is a problem with your question. You see, selbstlade is not a brand name. It is German for "Self Loading". In other words, an automatic pistol. And there were several guns that COULD be yours. If you can repost with ALL of the markings on the gun, and it's condition, we may be able to give you a rough idea- but without knowing make and model, we can't.
Value of ANY gun is based on the exact make, model, and condition. Unfortunately you have given us none of the 3 things we need. Selbstlade is not a brand name- it is German for "self loading". We know that you have a German .25 cal automatic pistol- but that's all. Sorry-
No such model made by Walther
No such model
5000$
Without more specifics, 10-1000 USD
$250-$350
5000$
Please describe your Walther in more detail - can find NO references to a Model PK100.
What is the value of a Walther Model II .22 cal. 9 shot magazine?