My mast top transducer got wiped out by a 200 kph seagull or just the wind during hurricane Odile last year. Since I am here in Mexico the final costs with replacement (no warranty), taxes, shipping and long waits on hold to Garmin, in the end cost me about $1000.
The replacement transducer sent would pair with the original Nexus WSI box. They then sent a new WSI, transducer at additional cost, plus more Mexican tax and the return of the first transducer. This new system came paired, but after it was installed it didn't read the speed/depth hull transducer or send it to the gauges. So more time on the phone and making up cables and reprogramming (with online help from support) from my laptop.
After three months and a grand it is up and working again. I enjoyed dealing originally with Nexus, but my list of vendors I'll buy from in the future is diminishing.
The original Nexus installation was very simple, but since my wiring from my first system was still in the mast I would have been better off buying a wired system.