Having driven both I would hold out for the Boxster. The interior in my opinion is much nicer (not as much plastic), the engine is more reliable (really? yes), and I think it looks and handles better.
It is completely up to you. I would just recommend you don't stretch yourself buying a car. If it is just a fun car and not your primary car, I would go for a 30k mile '98-'99 and get a $3k extended warranty, then start saving for other out of warranty repairs. That would probably be close to $22-24km depending on the mileage.
I would say wait (as hard as that may be) until you have more than you need for just the car.
Hope this helps!
