I recently went to the Singapore CX office to exchange a full fare ticket (denominated in HK$) for a OneWorld RTW ticket ex-Singapore. RTW prices are 20% lower in Singapore. After waiting for 2 hours for the ticket to be issued, I was told they have to charge me the ex-HK fare because, they said, the original ticket is in HK$, so charge HK fare. I wonder whether I've been ripped off by CX.