That answer is going to be all over the ball park. For instance, a locked up motor that's covered in corrosion isn't going to be worth nearly what a clean motor that hasn't been run in a while is worth.....Well , say for a non running 9.9 or 15 ?
I got one of those, a 73 model in the Home Depot parking lot for free. Was in amongst a trailer load of outboards headed to the scrap yard. After cleaning carbs and replacing coils, runs perfect. A low hour motor. I had several I didn't need one time I put on Craig's list for free and no one wanted them. Dad sold them for scrap. Now I wish I had them back, ha ha.my really nice & really clean locked up 9.5hp was $50 cdn and lives !!!