I had a 78 model 250, but essentially the same bike. I rode it hard.
It is not a common bike and probably has some collection value. The engines are tough. (most of the bike is fairly tough and durable.)
Not as powerful as it's competitors from the day.
It's a heavy bike for it's intended purpose.
The stupidly designed drive-chain tensioner will loosen easily. It's one of those spiral disk types that you rotate and click a notch in a spiral plate. If you buy it and plan to use it for more than street and fire road riding, find a better way to keep your chain adjusted.
I got the bike in a trade from a desperate friend. He had ridden it all through high school and a short while after. As long as you use it as a it is intended, street and light off-road duty, it is really a nice little bike (especially for a beginner.) I made the mistake of abusing it off-road and I wore it out rapidly.