It's the baby boomers plain and simple that are driving up the cost of everything, including fenders, guitars and basses that remind of their youth. That said. I have played 70's fenders at GC Hollywood, along with a 50's p-bass and wasn't really impressed by either one, I suppose if they were some of the good ones, no one would let them go.
First bass I owned was a 70's p-bass with a pretzel neck, only way to not get it not to buzz was to have the strings really high off the board. A lot of the old ones you find for sale are unremarkable, which is why people let them go in the first place I suspect, when you find one you really like then that's IT! Like the fella up a few posts said, find one you really like and don't look back, doesn't have to be a fender (unless you are a baby boomer, or subscribe to their delusional self importance about their (apparently the whole generation gets credit here) generation and how they changed music,.........thank god someone invented punk rock to kill the overblown 20 minute drum solo that 60's rock turned into!
RANT OVER!
the moral of the story is find the one you love and it shouldn't really matter what it says on the headstock. By the way I have played newer fenders that sound and feel real good, like the 60th anniversary one, and an 80's bullet by squier. In case you are wondering I play a Reverend PJ. Goodluck!