Maximum mileage 986/7 you'd consider

[pedalguyeric]

Hello, Newbie here in the market for an 03-08 986/7 S. This will be my first Porsche, I've been an Audi owner for almost 20 years. I'm from the Northeast so a fair number of cars available from CT, MA, NY, and NJ. My question, what is the maximum mileage 986/7 you'd consider? This will be a fun car, I estimate 3-4K miles/year. My plan would be to keep the car forever (the Missus has agreed to a Boxster purchase this time .... not sure I'll be able to convince her again!). Most of the cars in my area are being sold through used car dealers so they have no clue beyond the CarFax about the car's history. I will get a PPI. So all things considered equal, not knowing a good history on any car, at what mileage would you not even bother test driving it and spending the $$ on a PPI.

Thanks in advance!