Wow, what a dad. Mileage is one of those things that mean nothing to me. It all will depend on how much it was maintained. If it was done properly then the mileage does not matter as much as one with low mileage and no service. An example would be my work car. Bought new in June 2009 and now I have 73K on it a year and a half later. But it has oil changed religiously and service done at the proper intervals. Whoever buys it will get a great deal because the price will be low for the miles but the quality is top notch.
If I were you I would buy a reasonably priced one for about $25K and ask if he is willing to invest and bank the other $10K for you and just leave it alone. That is what I would do.
1997 Range Rover Beluga Black
1995 Discovery 1
1999 Discovery 2