if your going to buy the whole kit your wasting your money. only thing that matters is the muffler. thats where you get your sound and performance from.
i bought a borla muffer brand new on ebay for 60 bucks. and had 2 1/2" pipe bent from the headers to the muffler for 100 bucks. and didnt want a tip so i left it open after the muffler, so for 160 bucks i got a full 2 1/2" borla exhaust. the pipe is all the same there is no reason to pay a high price for a name. when the only thing worth paying for the name is the muffler. now a tail pipe woulda costed me another 50 bucks most. and then of course u need a tip, which is like 40 bucks on ebay. so it coulda costed 250$ but thats still cheaper than any exhaust system out there. arnt the gibsons going for like 700 bucks? i dont konw about you but i would rather take a few extra hours and save the 500 bucks and buy something else. thats a body lift or offroad bumper, or something else cool for your truck.
also. you dont have to rebend all your pipe. you can have the muffler cut out and the new one put in with all your original pipe. it will work just fine. and then you only have the cost of the muffler and the instal. i know my muffler shop only charges 30 bucks to weld a new one on.