[Who?]

For me, it boils down to relationship with and the reputations of the vendor/muffler shop.

If youve been going to a muffler shop for years, and you know the quality, by all means. With fabspeed (or other recognised vendors) you know youre getting quality, and for me, thats enough of a reason to save the hassle and pay a proportional premium.

That said, i wouldnt go to a muffler shop with a photo of someone elses product and ask them to replicate it. It really depends how strong your moral compass it i suppose..