So what did you end up buying? I read that you are searching for a WRX or STi. It is tough to find anything newer than 2002 without spending over 10K.
I bought my most recent BugEye (2002 WRX) last year for 10,200, it has a Borla Hush muffler on an Apex'i midpipe/downpipe. The only other thing it had done to it was to have the turbo ported and polished. I get 18PSI boost versus the stock 12PSI, it was otherwise left alone. It is good to get one as close to stock as you can, or it will have been trashed by the previous owner, otherwise, why sell it?
It is rare to find a fully modded Subie at a good price unless the car is ruined or the owner is broke and desparate.