Good thread over here too (there is a very active forum for the 996 over on Rennlist):
Annual maintenance on 996 - Rennlist Discussion Forums
In summary, figure on $1000 per year. Up front costs *might* be higher if the car needs to be brought up to snuff, ie you may need to spend money on brakes in year one, but this repair will last for many years right.
DIY is key though...but that's the same if you have a Golf or a Porsche. Speaking of which recent reliablity stdies are showing the Porsche 996 to be very reliable while the Golf....not so much.
Here's my detailled post from the thread above:
************
My car will be rolling over 100,000 miles tomorrow I've put about 35000 miles on it in the last 1.7 years.
On maintenance I've spent:
oil changes - 7 at $100 each DIY.
coolant reservoir and cap - $200 DIY
replaced a rattling muffler with a used part - $200 DIY
changed brake pads all four corners - $500 DIY
a set of front rotors - $200 DIY (these were new but sold as used)
sparking plugs - $80 DIY
air filter - $0 *(got it free with a car I bought previously)
pollen filter - $11
lightbulbs - $30 (damn little marker lights burnout frequently)
tires - 1 set so far $900 (not counting my snow or track wheels and tires)
brake fluid flush - 2 times at $100 DIY (took a while to get it right).
ignition switch $80 DIY
battery - $120
inner tie rod end - $600 not DIY
So what is all that...$3840. Is that a lot? I thought it would be less actually. I usually avoid adding these things up but I figured since you asked I'd rack my brain. Looks like the oil changes, the tires and the brakes ate up most of that.
I'm not complaining though. I daily drive mine and most days I end up telling myself how much I like this car. It's a keeper.
Upgrades added a bit by the way:
lightly used PSS9 coilovers - $1100 DIY
used H&R sway bars - $500 DIY
alignment and corner balance - $500
console delete - $150 DIY
track wheels and tires - $2000
snow wheels and tires - $1500
roof rack used $200
Geez - I don't want to add that all up again in a big hurry. I could have bought a nice used Honda with what I spent!! I sure would not have wanted to pay somebody to all of that work...figure on nearly doubling it!