I would stay away. It sounds like you will be dumping a few hundred dollars just to get it into a good trail machine that doesn't look all that great. The cost of parts adds up fast, very fast. Just fixing the "BAD" stuff and your looking at about $200. Then fixing the other things and your out lets say another $200. Now you have $750 in a machine that could still need more. That is now in the price range of a nice runner that looks good, something that you won’t have to question what could go wrong next.
From what it needs I am guessing it has not had the easiest life, the description makes me think it is like most beat machines and will need most of the non engine bearings replaced along with the brakes gone through.
1984 Yamaha YT 60 Tri Zinger(current project)
1983 Yamaha YTM 200 (rear suspension kit)..... long term project
2004 BMW R1150R
1972 Honda CT 70
2007 Lifan 110