I wouldn't pay more than $350 for it, and IMO they are cheap because it's "stock" and used. Obviously an improvement over the stock one on the sport, and it was kind of a "can't hurt" kind of deal for me. I lucked out and had a buddy do the install for $40, which obviously is a nice bump.

I built a custom xpipe for my Nismo and took the resonators off. It sounds epic now!

Intake or Nismo exhaust first?

I personally have FI longtubes and full cat-back with 18" resonators on my nismo, but to be honest as much as I have the opportunity to drive my car I should of just kept my stock nismo exhaust and added the motordyne test pipes to give it that extra sound and power. Not that I would trade my current setup for it but for the money and the power the motordyne pipes will give you its worth it in my opinion. Do some research on them, from what I have read up on they are the best for sound and power gains. Good luck

Honestly, the nismo exhaust, from what i've read, is only 7hp over stock...

So for $350, i think you are better off buying a used exhaust that someone is selling on the forum! I mean, aftermarket exhausts are supposed to produce higher numbers than the nismo right? I saw some that gave the car 20+hp from a full catback.

I just think the sound of the stock nismo exhaust is to quiet. It needs more umph...

If your going to stick with your Nismo exhaust and want HFC's, get ARK's resonated Cat pipes. You get a louder exhaust with HFC and no rasp. If price for intakes are a concern, AEM's can be found for under $400. If you still want more, Motordynes M370 intake manifold will give your exhaust more growl, more mid range, and reduces rasp (don't ask me how, but it does for me).

With those mods, you have gain power, get HFC's , have no rasp, and gain volume. If it isn't loud enough, throw on AAM short tails. You won't be complaining about a quiet exhaust anymore.