G'day!
First off :
Thinking of buying a Boxster ? - MUST READ !
140km is only about 86k miles, there's several on here with over 250k miles, so for the age that's basically low mileage still! check out
How Many Miles Are On Your 986/987?
It seems the issues most people see regularly are more age and/or lack of upkeep related than pure miles... clutch, suspension, water pump, AOS, various rubber parts etc are all going to be on their way out at 15-20 years if they've not been done already.