which is better?
 

I was wondering which would be better for cost/HP gain ratio, spending around $3K for bolt on mods,(i.e. catback exaust, test pips, cobb AP, intake, lightened pulleys, dyno tune) or spending $5K on a supercharger?

I think you already know the answer to this.

i prefer the sound of tt over sc...

3k = 100hp
5k = 200hp

...

Well the SC is the better choice. But your looking at about 6k for a SC, then if your not installing yourself add another grand or so for install maybe some mods to go along with the SC. Then of course wave bye bye to your warranty. At least you can switch out intakes or exhaust easily if something ever breaks on the car. Also most those parts you named can be used with a SC. I'm not down playing the SC its just want you want and can handle. A SC is about 2-4 years down the road for me.

SC is going to cost you more than $5k. Think of the supporting mods required for a reliable build. :tup:

+1. Supporting mods are what drive the cost through the roof. And then funky things start breaking...

And sound is of course, all that matters!:tup::roflpuke2:

When considering cost per HP gained, the obvious answer is a Supercharger. But as most said there is so much more that goes into installing a reliable supercharger. IMO you should start with the bolt ons then add the supercharger later on. Being that this is your first post I'm assuming you just got the car. Take the time to get to know the car with each added part. This way when you go S/C you will know if the car develops any issues.