GPS tech (Garmin, Hammerhead, Wahoo, RWGPS, etc)

I want one, so I can give my old unit to the missus. But I don't want to pay £500 for it. That's fuckin' redic. I also don't want one now because it will be flakey as fuck because Garmin devs are clearly animals that have been brought back to life during secret cold war russian experiments..