I don't sell them, personally I hate them, you spend all that money thinking it will be leak free and unnoticeable until you flip the switch. Then, after you've installed them (and can't get your friggin' money back) you find out they don't seal completely (annoying exhaust leak), and they're not all that loud. If you want my opinion.... don't buy them, save yourself 350-400 dollars and put it towards other (better) mods.
BTW, here are the prices....
-Quick Time Performance- $395.00/pr or $199/ea
-PFYC.com- $289.00/pr or $148/ea