Just some notes, as a longtime Rhodes owner whose father also went through three of them:
There is no specific difference between a 'Fender Rhodes' and a 'Rhodes'. The name change was strictly business related, and had nothing to do with the way the units were built, which evolved continually over time. That, in turn, is a reason why you shouldn't get too hung up on year of manufacture. The Rhodes piano's manufacturing history is actually kind of complicated. Different units built in the same year can even sound a little different (sometimes the factory made changes mid-year), especially when you're talking about buying a used instrument that may have gone through multiple owners, who may have done different voicing or different modifications, according to their taste. The only really major difference in general(major meaning it has a noticeable effect on the sound) from one manufacturing run to the next, is the tines.
As I haven't shopped for one in a while, I don't know what people are typically charging these days. That said, I feel like $700 is a bit much for a unit that needs repair, but that may just be me. Tines are not hard to replace in terms of skill required, but they can be a pain. Typically the tine base is aluminum, and the screw holding it in is steel, meaning they can seize up after having been connected for 30+ years. Last time I replaced one, it took two pairs of vise grips and all the strength I could muster to get the screw to loosen up.