What's It Worth Humminbird 998c si

I figure you fellers would know best. I bought a new Helix and selling my 998c si that works perfect and have no idea what's it's worth. Bought new in 2013, have a new unused puck and the si transducer that came off the boat. Unit has 673 hours.
Any of y'all have an idea on price? I've looked around on the internet but not finding much that's recent...Thanks for any help.

I got this on BBC for sale forum. It might help you a little.

Used Humminbird 898 SI /DI , 259 Hours , Great Condition , Always removed & stored after each fishing trip.



$400 TYD

I saw that, I've already gone through the past year of BBC for sale posts, and could find a 998c si that had a price on it.