Re: Mercury Motors
With out knowing condition, or specs only going off of hp of the motors. (also the 25" shaft if thats correct, it is a odd shaft length for that hp class of motors)
I would say $900 for 9.9, and $1200 for the 20hp assuming in good cosmetic and mechanical condition.
I also agree that NADA is not a good reference for boats and outboard motors. Local markets will trump the book value. Every boat and motor I have sold was above the book value.