I agree Jim, they hold their value. In fact, I bought mine new in 2002 for $950. I'm sure I could probably get more than that for it now. As far as changing Ric's over the years, they have stayed much the same in overall design, with small changes. I can tell you that quality has overall improved. I owned a 1963, model 330 when I was a teenager and the current 330's are much nicer and better built. Similarly, I find the current 4003's to be equal to or greater in quality to my 2002. They added a push pull knob to the newer models as well, to give an additional treble boost, if that treble tone is your thing.
Paul D. Boyer has written a book on the history of the Rickenbacker Bass which is excellent.
I also happen to be one of those guys that doesn't like the changes that Gibson is making to the Les Paul.