A lot of the cost's on these "elite" brands are due to R&D. If there are less than 10,000 Z's being purchased per year, there will be fewer looking to get an exhaust (or any other after market part.) There are a lot of Mustangs, Challangers, Camaro's, Vettes, Civic's, etc out there that can justify a lower price to increase volume sales.
The only elements you can judge objectively are fit, finish, welds, and engineering. Judging subjectively (our own opinions) are sound, aesthetics, and installation. If anyone is basing their arguments on the latter, reevaluate and re-present the argument. Ebay exhausts have a bad stigma, but like it was mentioned before... they are just pipes shaped and welded. We aren't risking much investment in trying an inexpensive brand. And if we happen to like it, even better.
To hate on other forum members because you have brand X, and you have brand Y is downright ignorant and distasteful.
Edit: this was more so in responses to the messages prior to page four, just trying to make sure there is no confusion
