[purplept]

TaylorMade,
I think many of the PT Forum members have struggled with your interest in getting the most performance increase for the least money. I know I was in the same position when I bought my 1st PT, a 2002 5-speed non-turbo (the Turbo came out as a 2003 model) about 1 1/2 years ago. I don't have a short answer to your question. However, my story might be insightful as you begin your PT performance enhancement journey. I tried the typical upgrades such as:
1) Headers (tried Hedman, ended up with JBA)
2) Exhaust (Borla Euro spec catback duals)
3) Air Intake (K&N FIPK)
4) Throttle body spacer
5) Short-throw shifter (Hurst)
6) Lowering Springs (Eibach Prokit)
7) Upgraded anti-sway bars (Eibach)
8) Strut Bar (BTG)
9) 19" Wheel Package (Yokohoma Parada Spec 2 225/35/19)
10) Roll Pan (PTeazer smoothie)
I still wasn't satisfied with the engine performance after all the upgrades. I never did a dyno test but my best guess would be about a 15 horsepower increase. However, I was very pleased with the handling improvements. After keeping the car for one year I decided to trade it in on a PT GT 5-speed. Yes, I lost several thousand dollars, but I'm very pleased with the stock performance except for handling. The other option was to install either a Whipple supercharger or more likely a Hahn turbocharger kit. I didn't do those options because:
1) I'd jeopardize the factory warranty to some degree
2) I'd still have the lower performing drivetrain (brake package and transmission, not the better drivetrain included in the Turbo package)
3) The cost for the supercharger or turbo would have been close to the amount I'd have to pay to upgrade to a new PT GT anyways

I'd recommend starting with a good air intake or just bite-the-bullet and get the Hahn turbo or Whipple supercharger. But be warned, you probably won't be satisfied with doing the "minor" upgrades. Part of the fun is the journey of experiencing the various upgrades and personalizing your car. The PT design has a strong attraction because of its unique body design and flexible interior and really is fun to drive with enough modifications. Enjoy your journey!