John,
I'll try to help but without more information and photographs, it's a bit difficult.
First, there were thousands of these pistols made by DWM and sold to the commercial market by Krieghoff.
Most backframe marked guns go for $2000 to 3000. These are common and are basically Weimar Era guns made by DWM, not Krieghoffs as such.
Now there are side frame marked guns with fuller elaborate Krieghoff lettering and some are actually genuine. Standard 1920's era DWM guns are frequently "improved" with the Krieghoff side frame inscription and are not genuine. The difference between the honest inscription and counterfeits is fairly evident. Caution is urged. Honest ones can command a higher price than the back frame. Maybe $1000-1500 more.
The following link to Simpsons will give you an idea about what DWM manufactured commercials sold by Krieghoff are going for.
http://www.simpsonltd.com/index.php?cPath=179_247
Hope this helps.
John