You might get a few bucks on eBay or Craigslist but they're outdated and no longer supported. Unless they had an old boat and limited funds, I don't know anyone that would drill holes in their boat to install 10 year old chart plotters.
'97 330 Sundancer, Raymarine C80 suite with radar, Mercury 310 Hypalon w/8hp Yammie 2stk
Engines
2X 454 carbs w/ vDrives
The Lowrance unit is the same as what I had on my last boat. It's not a bad unit. It has nema 2000 and there are decent accessories for it. I had trim tab sensor and fuel flow sensor added so it was kind of good for the day. I expect you might get something for it on eBay for someone that wants a second head unit. If I had my old boat I would have bought it and set it up side by side and used one for sonar and one for chart plotting
I had one I bought used. The unit worked fine. The antenna went bad. Too much good money after bad to fix it. You might get 25-30 dollars for it. Give it to someone in need.