Ouch, that is one of the harshish stories about buying a 2000 boxster I have heard. I bought my 2000 2.7L Boxster in 2006 with 43K miles on it, it now has 70K on it. The car had 2 previous owners and it has been very reliable (except for some of the adventures I have had with modding the car). Sorry about the problems you are having.
Ed