I noticed from my last couple of purchases on iHerb.com that it is now doing currency conversion to AU$ itself even when I choose US$ as my preferred currency. I always preferred to pay US$ and get my credit card to do the currency conversion because the CC gives a far better exchange rate. iHerb.com does not even tell the exchange rate they would use and it's completely opaque to the buyer. If I choose to pay using PayPal, that is also automatically converting the currency itself (and take a big cut) without even informing me.
I find this behaviour quite appalling. What can I do about it?