I got a cheaper used radar/chartplotter last year ... b&w older model, someone else's castoff as they upgraded to colour.
I got it mainly for Swiftsure trips, after a scary incident in the fog in the shipping lanes. Wherever it was, the horn on that fast mover was LOUD and sounded close ... but we never did see it to know for sure. <shudder>
Anyways, it figures that once you get radar installed, you then don't fish any foggy days! I only needed the radar once last season, coming back from Swiftsure ... we were out of shipping lanes, but we could not get up to plane without a better idea of what was coming up. The radar system paid for itself that day, would have been a long trip home without it.
Funny thing is, the unexpected part of getting this system was how much I now rely on the built in chartplotter. I've had a gps for years, but it is great having the big screen right there, both for navigating and fishing.