Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
lol chop the muffler and weld a straight through pipe and new tip, all up $25.
If it's just the cat back you want, $220 shipped, add the $40 for the resonator.
Do you know a price to ship to New Zealand (Auckland), or a good person I could get from in NZ? =) Thanks