ick, another silver subaru. i know price was prolly more of a concern than color, but silver is soo corporate/economy/rental mobile color.
aside from regular scheduled maintenance not really much to watch out for. a big problem with these cars is previous owners. I'd take a real close look at the engine bay to see any signs of modifications.
fred told me a good story the other day about a kid who bought a used wrx that had been modded and returned to stock. the car ran like complete trash and a couple of these "forum tuners" (yeah they are on unysoc) looked at it and couldnt figure it out. fred found some bullshit bleeder on the factory boost solenoid..then wait for it...
he found a UNICHIP piggybacked onto the ecu. yes i said UNICHIP. go google that if you dont know what it is. for those of us from pre-newb era subaru recognize this as complete vodoo majic black box electronics.