Along those lines, might be too much, but I wonder if you could tell if it has the stock water pump, alternator, and front wheel bearings. I replaced all of those things after 100,000. I'm on my 3rd water pump at 180,000.
If you do buy it, I'd be happy to be a resource for you. I'm no mechanic, but I've driven the same 99 7.3L since 2002 and have performed pretty much all of my repairs. I like my truck, but as 1ags has stated before, be prepared to have some weekend projects carry over into the week. My truck has been very reliable, but it's currently leaking diesel out of my fuel bowel drain line. I ordered a new valve and will put it on, probably take an hour or so. I've done it before, no big deal. But it is old and these things do crop up.