This has been a problem for me - rates are quoted in US $, but then billed in TB (and at a very unfavorable rate). You take a double hit if you charge to Amex (US based) because they then convert the TB back to US $ again at an unfavorable rate.

I don't understand why they can quote a rate in US $, but charge a different amount in the local currency as opposed to quoting in the local currency (as they do in Malaysia) then you can do your own math.

This is VERY frustrating - I was, for example, quoted a rate of US $65 given starpoints for a rate of $54(!) but the actual charge was more like $70 - all of this is before taxes. When I questioned the point credit (which due to my long stay actually added up to hundreds of points different)I was told I would need to send my folio even tho it was clear that the rate quoted was US 65 ++