I got my WRX 2 summers ago for $15K. It was an 02 with 36K miles. You can get them up to ~215whp with just exhaust, a chip on top of that and you're looking ~250whp. The motors will normally have a little bit more torque than HP also.
He could probably get a higher mileage 02 for 11K and then use the rest of the money for a 6speed swap since the 5speeds obviously dont hold any power (see the top thread in the Suby section). The cars are showing to hold up very well at higher mileage as a lot of 02s are seeing over 100K miles now.
