c/93 Borchardt

I live in WY and an elderly lady asked if Icould find a value for her C/93 Borchardt. Since I know nothing about this type of gun but new it had a luger history I found this web board to ask. It is complete wtih a shoulder stock and in good condition. I do not know what the Serial # is but I am trying to gather more info. An uncle brought it to this country with him before 1900. She is looking to sell this gun and needs to know a value. Thank you for your time and help. Wayne/ Olefish