I booked it out on NADA. Taking into account the age of both boat and motor average retail is $16,100. I wonder why the motor is 2 years older than the boat. Johnny Morris' Tracker Marine is way too big to have to use 2 year old motors on a boat. Very few even put one on a year model older.
If I were wanting that boat and willing to buy it I'd offer 14,250.97 and see the counter. Don't even round it off to the nearest dollar. That would give them something to think about, thinking you know more than you actually may, and you a bargaining point to start. Don't feel bad about offering lower than they want. You never know what they really have in it.