the mentioned 2000 S has ~6k miles per year it is right at the sweet spot in terms of use versus age to me. Sitting around is bad for a car. Stuff ages as well as wears out. And the recent repair history doesn't sound like it was neglected. While the recommended interval at this usage rate is 1 oil change a year, many don't keep records that long.
I love my '01 S Boxster but it gets only around 2k miles a year now...now have other priorities and other vehicles sit next to it. It gets better than normal maintenance. But is it a Miata in terms of simplicity? No. More features, more comfort, more complexity, more potential expense. Mine has been very very reliable and cheap to maintain over 5 years. But things can fail. Got a good dealer/independent-mechanic that knows Porsches handy?
All I know about buying a Boxster is on these
web pages.