I would be happy to sell you my STi exhaust for $200, especially because I think I paid $100. I am going to be checking today to see if I can use it for what I have in mind and I'll let you know if I can sell it. I regularly see those exhausts go for $100-$200 on NASIOC, so you can find one if you are willing to look.
The STi muffler is almost no difference in sound from the other stock exhausts. If you choose to go with the Maddad, Gabe always had good stuff.