[kk2002s]

I try and separate general car/sports car maintenance out, brakes, tires, tune up, etc. All cars have these.
It's the Porsche, European costs that you have to track to really gauge Porsche vs Miata, or what ever.
As DWBOX2000 said, parts $$ can be higher especially if you stick with Porsche only parts. Find the manufacture of the Porsche part can save $$ while retaining the same part.
As thstone said, It will be waves as you go for awhile with basic stuff and then it seem like everything wears out at once.
I just had my first 'have to go to a mechanic' experience in 5+ years/45k miles of ownership. It was emissions, difficult and time consuming to diagnose. $1050 later I passed state inspection. The shop's services were reasonable. Parts were inline with what I would have paid. I paid for their ability to track the issue down. I'm OK with that once in awhile
Do NOT try and justify cost to value, the only way you can justify the cost is to look in the rear view mirror after a sharp corner, a howling high RPM on-ramp, at your S@#$ eating grin on your face