What is a Collectable Luger

Hi guys: I appreciate all the response. I have only been with you about 3 weeks. I still firmly believe that big $'s are directly related to the importance that some well known collectors place on the collection of others. Case in point; A couple of years ago at a major show I displayed and sold a matching 1918 Erfurt with ZN stamped above the date. I have all the major books. Only place ZN mentioned [very briefly] is in Walters Luger Book. I bought it for $350 because it was unusual. One of the leading well published Luger authorities passed buy and looked at it briefly turned away while making comment ZN Huh! I couldn't even get him to engage in conversation about it--but then it wasn't in mint condition and was after all an import. [No it wasn't Ralph--he would never do that] I kind of figured that since the guy didn't have one these in mint condition that ZN just didn't exist. I like the forum and have got to know a few guys by direct Email. What is wrong with a $350 Luger that one can sell for $425 6 months later. That is if investment is ones primary objective. I think Stainless Steel Lugers are OK--even have 2--the 1991 Mitchell and one the 1900-2000 commeratives. Know the guy who makes them--Nice guy. But then I even have a luger capgun and a water gun or two. Thanks again fellows--Lets hear it for the little guys.