All this is just opinion and a little bit of rank supposition based on the 2005-2009 but this is what I would expect.

Average car on the average Dynojet will make maybe 355-360 rwhp on 87 Octane or 365-370 rwhp on 91 Octane .

CAI/Tune + 93 Octane will be worth around 10% over Stock with 87 Octane.
I used those because I have more data to compare.

Full Long Tubes + ORX + 3" Midpipe + Straight Through Mufflers will be worth around 7.5% more.

That would be roughly 425 rwhp.

Just my opinion. That and a buck will by you a cup of cheap coffee.

 

It's never cheap nor easy lol. Headers are always a PITA, and with CAI's in the couple of hundred range (or more) nowadays I don't consider them cheap anymore. Cheap was a $30 3 inch air breather, 150$ pair of longtubes, 10$ distributer recurve kit, a 150$ cam and a six pack with your buddies on a weekend. With a header/CAI/Tune/cat-back combos reaching well over $1000, nothings cheap these days.

 

Well said. Like you said maybe to some 600-700 is cheap for a Tuner/CAI but that is $20-23 for each hp if it gains you 30hp. Plus you know in the beginning the prices are going to be high. Its better to wait and see the best bang for the buck on individuals cars and not the sellers.

 

No kidding. when the GTO's first came out the cheapest header was like 600$ I can now find them for a hair under $300. It's still messed up my brother just bought a set for his 94 silverado for less than $150 .

 

true. the word "cheap" means different things to different folks. 700.00 for 400rwhp is cheap in my book.