I am going to be brutally honest here. The people that own this horse have probably expended all their money, time and resources on this mare to try to get her fixed. I'm sure they have sent her to some very reputable trainers and the trainers probably wouldn't ride the thing. In her area, I'm guessing she has a bad reputation and no one will buy her, which is why they are selling out of state.
Notice, there are no riding pictures of the horse, notice they call her a "project horse", notice, a mare with her breeding should be selling for over $10,000. The horse is crazy.
I'm going to make an assumption that you are not a professional jumper trainer. Now if there are professional jumper trainers who have refused to ride the horse, what does that say about her?? Does that say that anyone can ride the horse?? No. That says that this horse is borderline unridable, even by people who professionally ride, train and show high powered jumpers.
Run, far far away.