I live in North Carolina and when you register a car that you buy from a private seller NC DMV uses the Black Book to determine the value of the car which is used to determine your "use tax". If you call the NC DMV (main office is in Raleigh) you may be able to ask what the "tax value" will be for the car. They'll ask for the VIN and give you the value over the phone (at least they have done that for me on several cars I was interested in buying). The Tax Value they give you will be the Black Book Value. I'm not sure if they adjust for mileage, so the value you get may be higher than true Black Book value since your car has over 100K miles on it.
Good luck. Hope this helps.