Need advice on Lowrance fishfinder/chartplotter

A friend of mine has a new in the box Lowrance Elite 9Ti fishfinder/chartplotter with all the accessories except it does not include the tranducer. He installed the transducer on his boat but then life intervened and he never installed the fishfinder. He wanted to give it to me but I don't really have a use for it since I run a very similar Garmin unit on my boat. I believe the unit was purchased about 5 years ago.
Any idea what this unit might be worth? Where would he list it for sale?
Thanks for your help.