http://mike.focke.googlepages.com/mikesporscheboxsterwebpages .
Poke around on that site (read at least the first 3 or 4 web pages) and get a feel for what ownership is like, what the risks and rewards are. I'd only buy if I had located a well though of Porsche maintenance facility as, without that (and given that you can't self maintain) I'd think ownership would be impractical.
I've never owned a Boxster and lived in the city where I was subject to parallel parking and the differing bumper heights of SUVs. I'd worry about that where you live.
Having said that, I'm on my second Boxster, both used, both quite trouble free over 5 years. I do do some routine maintenance myself and for that there is an enormous amount of help available...write ups (some of which are on that site, others are linked to). I use independent mechanics where I can, some dealership services when I need them. Dealers vary. But then that is true for all brands.
Do definitely get the Pre Purchase Inspection (PPI) done.
It is a wonderful car.