The most important variable is probably is the authenticity and ability to prove so. Then, assuming it has been authenticated by one of the well known people that do this and have excellent reputations in that trade, it is the point type which is an indicator of age combined with how well it represents the point type. Then color and material also play a part in it. Where it is found, assuming it is a place to be legally hunted, is a consideration, but not as important as others. That is my opinion from my foray into the collecting world, others may disagree. A lot is based on what an individual collector likes.