So I can assume 90% of the people here will be buying D3. If you're like me and not wanting to risk not getting it on launch due to some dodgy shipping here is how you get around the region price fix on the digital copy (You end up paying $70 AUD which is $10 cheaper than the Australian price but still $10 more expensive than the yanks..still its $10 bucks!
Log into https://us.battle.net/account/management/get-a-game.html
Note that the balance on the right-hand side most likely reads in AUD, as does the price of Diablo III
Click Transaction History > Balance History
Select US Dollars from the currency drop-down menu
Click Games & Codes > Buy Digital Games
Diablo III should now be listed in $90 SGD (i.e. $69 AUD)
Continue ordering as per usual. The game version is Global, so you're not getting a Singaporean version here.
I just did it and it works; was charged $69.xx AUD