I realize you want to defend your purchase, and thats ok. I've been through all this before and you probably would have gotten the extra hp from the tune and a simple K&N.
In the end it's your car and your money spend it how you want.
You're probably not going to "feel" anything or run better times with a tune and filter box, so unless you race on the dyno those things don't mean jack.
The aftermarket TB has got to be the biggest scam for these cars

the stocker flows plenty.
Nitrous and some gears are the best bang for the buck
Blower