I am close to purchasing a 2000 like new Flagstaff Model 176SDLTD pop-up camper. Unfortunately, NADA does not list this model in its price guide so I don't know whether the asking price is reasonable. The NADA guide lists the 176LTD but not one with an "SD" in it. Does anyone know what features the "SD" model includes that are not in the LTD? I tried to find some info on the Forest River web site but they don't even list a contact phone number on their site. They obviously don't want consumers bothering them!