Whoops, just looked that up.
www.homeaffairs.gov.au/Using the customs example of purchases over $1,000 I calculated the following:
C4Customs value (Cval) AU $1,353.50
Customs duty (Duty) @ 5% of Cval AU $67.68 (Payable)
International transport and insurance or postage (T&I) AU $291.52
Value of the Taxable Importation (VoTI) (Cval+Duty+T&I) AU $1,712.7
Goods and Services Tax (GST) @ 10 per cent of the VoTI AU $171.27 (Payable)
Total payable Duty + GST AU $238.95
C4 board + Paddle $1,883.97
You could of course tell customs that it costs under $1000 and not pay any duty..... hmmmm but that would be illegal!
Just realised the $995 ULI was for an 11' inflatable surfboard not a sup.