Congrats to the OP for posting the EXACT magnitude of the ripoff, in Dollars and Cents, of this abomination. And it is true that even if the transaction is posted in US Dollars, most American cardholders are charged the 3% transaction fee by their bank, IN ADDITION to the ripoff at the merchant's end.

Most discussions of this in the travel magazines are vague and warn against the practice; here you can see what you're "spending" to spend. A total ripoff, and a VERY lucrative, undeserved one. Don't fall for it, and DO COMPLAIN and INSIST on the merchant making it right, and tell them why.