Haha, yeah, not everything is made overseas
There is a lot of R&D in a good system, you can use basic techniques and generic stuff for a reasonable exhaust sometimes, but if you want something tuned on the specific model of car and in the case of the Z, something that has the crap tuned out of it, it'll cost ya.
Mustangs? yeah, they've used the same engines for a bazillion years, essentially (i know they've updated them) but they're also large displacement V8's and the engine makes the noise no matter what.
I'm not saying i agree with the current prices, but just look at the price of metal increase in the last 5+ years, it's sky-rocketed for the good stuff.
I could buy a really good system for not far off two thirds the price they are these days
