Hey mate I had the same car except in manual form with 269,000kms on it when I sold it. Check the CVs, the Airflow Meter (AFM) and the shock absorbers. I can tell you I got quoted about $500 just to get the rear shocks replaced!
Depending on when it was last done, you might be up for a timing kit. I had that done and also had to get the water pump replaced aswell. That's pretty much the only problems I had at that age.
The AFM was most likely boned only because I had an K&N oiled panel filter in my car though.
I own a 2003 WRX now and I can honestly tell you there are still times I miss my TX5 because it was such a good car
