Maybe use the same rate of exchange for the options as they use for the iMac. ie the 27" the US is USD$1,999 vs in AUS at AUD$2,199 which is an exchange rate of 0.91c. So my guess is the BTO options will be calculated as the same rate, summarsied as -
- 3.4 GHz Core i7 (USD$200) AUD$220.00
- NVIDIA GeForce GTX 680MX with 2 GB of GDDR5 (USD$150) AUD$165.00
- 1 TB hard drive upgradeable to 3 TB for USD$150, AUD$165.00
- RAM upgrade options ranging up to USD$600 (AUD$660.00) for 32 GB of Apple-installed RAM
- Fusion Drives for an additional USD$250 premium AUD$275.00
- 768 GB all-flash drive as a USD$1300 AUD$1,429.00
SO a fully BTO (with out 768GB Flash) in AUS will cost AUD$3,684.00 or AUD$3,024.00 with user upgrading RAM.
My 0.2c