Hi Dave, first off welcome aboard
That is an interesting scenario. I'd be hesitant without at least sampling the list before purchasing. Ideally I'd try to work out a scenario where they earn revenue based on any completed sales so that you are assured you are not stuck with nothing more than a large bill. Do they have anyone else to sell this list to? If not, I'd consider your position strongly and devise a plan so that you can take advantage of the potential revenue while sharing in any profits as appropriate with this person. Personally, I wouldn't throw down 35k on any list. I can go find and call on people myself for much less.