fren wrong forum lah... u should go to those MAS site... hehehe...
anyway, the simplest method is to do markup, u never know the hidden cost lor... i normally calculate base on 1.8, cos sometimes GST, fuel surcharge etc... still can cover abit...
In your case where you bought something and you found the bank charges you 1.7 is because your bank need to earn something wat heheh. If not what you intend to do? tell them to charge you cheap as you found out someother firm charges less? If you are using DBS credit card to charge..you are stuck with their rate. Unless you have another credit card from another bank to use for your ebay purchase.
And what's the use of getting everyone to update this thread with new exchange rate. Everyday or even half day, rates can change in real time. Plus what if I want Euro or Yen or Yuan or Malaysia? hehe... and it might not be to change to singapore currency..eg.
Like Del_CtrlnoAlt mentioned. Best to go to a MAS forum heheh.....