Swap out what you want to keep. A prospective buyer isn't going to expect what he doesn't see when he looks at it. Electronics aren't going to add that much to the resale value of the boat but are going to be expensive to replace.
2015 Seaark 1872 MV CC Etec-90
Two Helix 12 CHIRP SI's, , MinnKota Riptide ST80/i-pilot Link, Bob's Hydraulic
2018 Robalo R180 CC, Yamaha 115
Bitter Gun Owner