Thanks for your thoughts on the extra charges for the AONE5 ex-MRU. I realize that these charges are, in general, not dependent on the ticket price but was just using the % calculation as a guideline. In the QF example quoted by number_6 the maximum extra charge shown was about US$800 (AU$1043) versus my quoted US$1800. Their example was 16 segments, mine is 18-- and almost all mine involve stopovers rather than transits- (as their example seems to imply).

Alternatively, I looked up the fuel surcharges for each segment and it seems that they would account for less than $400 of the $1800. Also I did a segment-by-segment summation of all extra costs (as shown on the ITA pages with itemized costs) and this doesn't add much. Re the credit card surcharge, that seems unlikely because I have not discussed payment details with them. Im hoping I can get a detailed breakout from them.