Somebody really used that coach. Mine is the same year and I only have 57K, but 200K miles on a ISM Cummins engine is nothing. So I would not worry about the engine. I would be more concerned as to the condition of the house part. If the previous owner took care of their coach like we do, it will still look like a new coach, but some folks just drive them until the wheels fall off and no maintenance on either the chassis or the house part.
I notice you did not mention the brand or model of coach. Can you be more specific as to what you are interested in.