That seems a lot to me too. I have a 1997 9.9, it is the same motor with a different carb, and it has been an excellent motor for me since I bought it new. Salt or fresh, I am not so sure it makes much of a difference, although I am sure others do. Mine has only ever been in salt, and there is no corrosion anywhere. If it runs good it runs good. Most of the corrosion type issues you should be able to see without taking the motor apart. A friend of mine bought what you are looking at (except with a short shaft, as is mine) this past fall for around $500, and that motor probably doesn't have 50 hours on it. But like somebody already said, it is almost a 20 year old motor, and they only cost around $1500 new at the time. It is also pretty easy to do most of the maintenance yourself, and parts are widely available. So if it runs and starts right up, and you could buy it for $5-600, I think you would be good. At $900 I don't think I would be interested. I am assuming a long shaft works for you. If the length is not ideal, I would offer less.