Hi Pommie , I bought mine here , from the local (NZ & Oz) rep.It was about $600.
Warranty? I haven't been back to my dealer ( & am not in a hurry to do so ) , however Bluefin guarantee that their tune should not affect warranty? - but I'll cross that hurdle if I get to it.
If my dealer wants to have a go at me about warranty , he could also question my exhaust,blow-off valve,actuator,wheel spacers.etc... I have made a choice to have my car the way I want it!