If you want it just to hang in your garage, that's not a bad deal. In fact, I would probably buy it if it were near me. Most of the Porsche bike ads I've seen have pretty high asking prices. The issue with those bikes is that they were never really that great. They were NOT lightweight like the ad says, mainly due to the component selection.
My Opinionated Comments:
-The brake line is an easy fix for anyone who's worked on those brakes before. Those are some of the best rim brakes ever made, IMO. I have a bike with a set, and probably have spare parts if you end up purchasing the bike.
-Those front shocks have always been crap. If they really need replacement, you are probably SOL. They are probably unobtainium, since it is a german shock that was never actively marketed in the US.
-I could be wrong, but I don't believe the cranks and rear derailleur are original. They look too new to me. (whoops... just saw that bit of the ad)
-Needs a new chain.
-Probably at least $100 for parts and labor if you have a bike shop get it running.
This is a much better deal:
http://miami.craigslist.org/mdc/bik/1416784509.html