just sharing . . .
I was right where the OP was 2/3 weeks ago. I'd found a highly rated bolt on axleback system from a race-related company I wanted to go with.
To discuss install, I drove to a longstanding muffler place in town, a Magnaflow dealer it turned out, and the owner was able to give me an X Pipe and MF axleback setup, with new tips (Silverline), installed, for less than the 'Race Catalog' Bolt On part I had started my thought process with. No special/insider deal. It was that because he stocked his MF stuff in quantity , he could give me what I wanted, exactly the solution I wanted, in terms of sound/performance/look, for that much less.
I gained a few HP, dropped some weight over stock, my 2011 GT's sound is now 'Medium Thunder,' and I saved enough for another mod. I smiled for a week.