should I consider an '89 735i

I found a 735i bmw in pleasanton, ca that is in awesome condition. the guy says that he hadn't driven it in a year, but kept it garaged. the problem is that he started it up for the first time in a year the other morning and a bit of smoke was coming from the tailpipe. he isn't quite sure if that is due to old gas that was left in the tank or if it is a worse case scenario. while the car was still being driven prior to this it was very well maintained. it has about 150k miles on it. he's asking $1,800 for it. should I buy or walk?

if you decide to pass up on that deal, please pass the addy my way via pm, would like to take a crack at getting it, proud owner of a 89 735il with over 200,000 plus, very happy with it. santa rosa,ca to there is a short trip at 90, lol