Also, Brian Corsetti has a blog on his website with several articles on what to look for when considering a purchase. Here’s a link to one of the articles to get you started.
Top 5 Things You MUST Do When Test Driving a Toyota Land Cruiser FJ60 (Buyers Guide) -...
I would buy two at once if I could find one being sold for $15k in the condition you describe. Current market, from what I can tell, for a rust-free, 5-speed, mechanically-sound FJ60 with a clean interior in pretty close to original condition and with less than 200K miles is $25-35K and up...