[Vwdiesel] Should I keep or bail now?

[Andy Mann]

Ok...I need some advice again. I have an 86 Jetta diesel that I
have currently about $600 into (purchase price + exhaust).  I need
to have a timing belt, starter and new tires put on. This would bring
me up to about $1000 invested. The car has 300k on it (mostly
highway from previous owner) and seems to run ok. The prior
owner seemed very responsible and kept all records...even oil
changes. He also bought the car from his boss who was just as
responsible I'm told.
 My question is....where do I draw the line? I'm told the injector
pump starts to go around 300k and cost about $900 to repair.
Clutch seems ok but don't know how much life it has left. Body ok
as well with a few repairs but looks fine. Interior fine. Is it worth
getting this car up to speed or should I just cut my losses before I
get nickled and dimed to death? This car was made in Germany
which I hear is a plus. It started pretty good even in the cold before
the starter went. No oil in anti-freeze or milkshakes when you open
the oil filler cap. The air conditioner even works! Waterpump,
altenator,glowplugs and brakes all done recently(by previous
owner).
What does the list think? Is it worth investing in or should I bail
now? What else can I look forward to going wrong? Any advice
would be appreciated.