I've owned this car for 11 years.
One of the best I've driven.
Car is now at 350K and yes, maint is expensive, but worth it.
Oil changes every 3 months and i would suggest owners budget atleast $1200 a year for maintenance.
Besides oil changes & tuneups -
ABS module - approx $300 to fix.
Heater core - @250K - approx $800
Window switch - approx $200
Rear antenna - approx $100
Incredible attention on the road, even for an 11 year old car.
Fast - comfortable - wonderful to drive.
I also own an S60 2.5T, but I find that I enjoy the C70 better.