It is a great car. Mine has only had a 3 issues. Each about $1000 at the dealer (2014 base). And the car was under warranty for each of those. The thing is Porsche Maintenance is "are you frickn kidding" expensive. Just this week they wanted to do a 6 year maintenance on my car for $1500. It is an oil change, brake flush, air filter, cabin filter and a bunch of inspections. An oil change is 350, brake flush 200 so all the "looking" and 2 $30 filters would have cost $1000. The CRAZY item is the brakes. If you take it to the dealer and say "change them" the bill will be $5000. Mine is a v6, I know the v8 has some crazy prices cooling tube but i dont know the details. Everyone is afraid of the transfer case, that also costs 4-5k. (I dont think there is a cheap way out of that). The car can be "affordable" but it takes planing. google cayenne transfer case symptoms and go drive the car and make sure you dont hear the noises (acorns crunching) people talk about.
Good luck and move slow. There is no such thing as a cheap Porsche.