As far as I'm concerned the money i've spent on my Meridian Gold is worth it. I've lived here for 28 years, and in the short amount of time i've been geocaching, i've been to some great places i'd never even heard of before.
I wouldn't advise anyone to spend their house payment on a GPS unit, but I can think of a lot of other ways i've blown a lot more money on something i've gotten less enjoyment out of.