The masts are 100% carbon, and a 4,6m mast will set me back about $1000. Now, multiply that by 4 and add a bit for a standard aluminium Hobie Tiger mast.
Steve, are you saying that a Hobie Tiger mast is $4000? Even if you're talking Aussy dollars that's $2,950 US. A replacement aluminum mast for a Nacra 6.0NA (the only pricing information I could find online) is $895 US complete.