[Steve Tinker]

There is a really informative article this month in Australian Unique Cars regarding the running costs of a Skyline R35 GT-R. The writer owns a Skyline & says its the supercar bargain to buy, but the maintenance costs are up there with the exotica. His car is for the road, but also used for track days.
He states that a few cars have broken their transmissions using the "launch" control which has now been modified with a softer control, but what is expensive is the servicing schedule for the GR6 transmission - the factory fluid costs (quoted all in $US) $80 per litre - and the transmission takes 10 litres. Thats $800 per oil change. Nissan Techs can read the peak gearbox oil temps and if the temps have reached 130 deg C, (about 3 laps of a track) you are up for an oil change. Regardless, Nissan recommend the gearbox oil be changed @ 3000km intervals !!!!
Diff fluid is more expensive @ $160 per litre x 3 litres - $480.
Brake rotors and pads are obtainable cheaper ex USA from AP Racing - rotors costing $950 EACH plus fitting and a set of Endless or Pagid pads will set you back $1000 - which is cheaper than OEM.
But tyres are the killer costs which in Oz costs $750 EACH for the Dunlop RSST run-flats - which don't last long, especially the fronts.
Currently, Nissan Australia specialised techs trained in GT-R's are charging $150 / hr for servicing.
I don't know how these costs equate to running say a Porsche GT3, but as with many things in life, buying something expensive is somewhat easier than maintaining it.
So. though the GT-R may make a Boxster (or a 997) feel like a donkey, you had better put some $$$ away for routine maintenance.......