Between an '02 Outback and an '05 LGT, I've put 160K on Subaru's in the last 7 years. I have replaced the rear wheel bearings twice on the '05, both times Subaru covered all expenses. That is it - no other unexpected maintenance.
Check into maintenance costs; while they may be fun to drive, keeping them up may break the bank. My mechanic gave a guy a quote of $2800 for parts and labor to replace the brakes and rotors on an '06 STI. I paid less than $700 for P&L on my LGT. P&L for the clutch on the STI was just over $2K, mine was under $1K. FYI - if you spend much time in the boost, you'll be lucky if you get 20mpg in the STI. My LGT is lightly modified (285hp, 300ft-lbs) but still gets 29mpg (mostly highway) with a "moderate" right foot.