That is a bit of a tough one. I would guess the motor is fine but would still bring it to a good Yamaha mechanic for a once over. My initial concern would be the fuel. Even with Stabil I wonder if it has gone bad after two years. I would also check the trailer as if it has been sitting on the tires they are probably suffering from some dry rot and have flat spots. Check the bearings etc...as well. As for the value, my understanding is it is a very slow year for boat sales so I am guessing there are some deals to be made. New a few years back that boat was about $25K on a trailer. I would think definitely less than $20K and you may be able to get it for $18K. That is a great and very seaworthy rig you would get a lot of enjoyment out of.