Insurance? My car insurance is not any different than my old Corolla, well maybe a bit more because the Prius costs more than my Corolla. Even if you had to pay more for the insurance (which i doubt vs. a VW), the money you save on maintenance should be more than enough to offset it vs. an old Jetta. (On the Prius, you don't change out your brakes until near 100k miles because the actual brakes are hardly ever used!) Hybrid batteries are getting cheaper (under $2k for
new hybrid batteries on old hybrids...you can get a used one for under $1k)...and they are proven to run past 150k miles easily...and most gets past 250k miles.
Lets face it, Jettas new or old have NEVER been known to have good reliability...so, you may save a little bit on gas (diesel prices are going up too!), you pay plenty for maintenance costs.
Even your VW Jetta does not get good ratings:
1999 Volkswagen Jetta Reliability - MSN Autos
I think that Civics and Corollas are the way to go if you're looking at old cars...built to last a long time.