[Perfectlap]

I purchased my car with barely 9K miles after four years. It was literally in showroom condition because it actually was sitting in the dealer's showroom. When I "inspected" it I had no absolutely no idea what to look for but didn' really give it too much thought becaue it was practically new...

Fast forward 60K miles later and I've had to do a very long list of repairs. So if I were in your shoes I'd be asking for service records. The longer the list of things that have been addressed or preventive maintenance that has been performed the fewer things you might have to do.
This car has some notorious weak spots like the coolant tank, the AOS, the RMS is prone to leaking (more of hassle than a mortal disease), of course the IMS needs to be addressed if its a single row bearing 2001-2004 and some early 2000's. Dual row bearings have had far better luck and some have not bothered to upgrade even after well over 100K miles. But those are mostly the 2.5 engines and not the S power engine. The IMS is typically replaced with the clutch and flywheel which can run you $3K in parts alone if you go with the new LN Solution bearing. Also, shocks and control arms on a sports car are not high mileage parts if you live where the roads are harsh and beaten up by winter. That's at least $2K in parts before labor.
In addition my catalytic converters didn't make it past 70K miles on the stock exhaust, another expensive item. Then there are the unexpected repairs like a starter or throttle body that might go, both of which I had to replace before the 60K mile mark.

Meanwhile there are folks in sunny climates like Southern California who have barely needed to fix a thing and are well into 100K miles of driving. I live in the northeast and my car is driven year round. And although its only driven on weekends it has still required significant upkeep well before the 100K mile mark. So again, if the mileage for the car you are looking at is over 50-60K miles, make a determination on how the car has been driven (year round), what repairs have been done, how often has the oil been changed and what sort of oil was used, and what major maintenance items have been taken care of (shocks, clutch/ims). Make sure inspect every panel of the bodywork for dents and chipping. Around here bodywork will run at least $600 per panel, with front and rear bumper work coming in a bit cheaper to repaint. And check that the HVAC is blowing cold air without issue and inspect the windscreen for any tiny cracks or chips.
The condition of the rear tires are also important to check as tires are not cheap for these cars, particularly in the larger 18" and 19" sizes.

If all this sounds good then have a Porsche specialist or the nearest dealer inspect the car BEFORE making an offer. They'll report what things need to be addressed. You can use that to come up with a counter offer price. I would hessistate to make an offer before the inspection.