Why is the Billyboat cat-back almost $500 more than the Borla?? I've looked at both and cannot see why besides it being polished and a big dual in/out muffler like the stock style.. The Borla even looks like it gives more performance, 2 separate mufflers and a built in H pipe, its 3inch and SS just like billy just not polished. Besides name I'm just trying to figure it out, I could understand the entire header back system being awesome but just asking on the cat back to replace the stock system for more performance..... Thanks.