Need help on Luger S/42. I have no clue! (long)

Well, today as my luck would have it I was approached by a gentleman who wanted me to help him sell his Luger. The bad part is that I do not know much about Lugers or their values. The good part is that this one was in pristine condition as it came out of the box. No holster wear, nothing. It is as good as you ever find one. Here are the details: date stamp 1936, marked s/42, 4 digit serial number, all numbers match including the mag, perfect blue (pristine), perfect straw colors on the trigger and lever, no sanding, buffing, or any other restoration marks, perfect grips, all inspector marks down to the smallest one on the barrel are crisp and clear. It is looks so good that I thought at first that it is someone's sophisticated restoration. Blue on the rotating pins is different shade than the rest of the pistol (i think it's the way they come). My first instinct was to buy it myself but I doubt that I can afford it. If i agree to post it for him how much should I recommend asking (he is not a fool and knows the pistol is worth serious money). What should I inspect the pistol for to see if this is a real masterpiece of a restoration (i doubt). I have not taken it apart but I will this weekend. I appreciate you helpful comments and advice.