What is the value of a first gen G17 with serial number EC117US? It has the NPv and eagle proofmarks on the barell. I have the original tupperware box and I beleive the old preban 17 round mags (2 good ones and one that is cracked). I use this for my range gun but keep it cleaned and shoot good amunition out of it. It is between 85 to 90% condition. Does anyone have an idea of a fair asking price?