Sharing updates on my attempts to add stops with ex-CAI DONE3 issued by QF.
Background
Initial ticket price was around AUD3980 ticket + AUD1290 for YQ/YR
Initial segment was 13 air segments, and 2 surface segment, open jaw at DOH
4 segment flown (3 inter Europe, 1 from Europe to Asia)

I tried to change my balance itinerary by removing 2 surface (replace with inter US) and add final segment to DOH-DXB

Was told by QF team that for ex-CAI ticket, they cant calculate the change cost, unless,
1. Remove cities that stop multiple times (I have 2x KUL and 2x DFW)
2. End it with DOH-CAI

After many rounds of attempts with different agents, it seems always route back to same agent that willing to handle but with above restriction. Others just said they cant priced.
So, I made changes according to above, and was quoted 4.9k AUD price difference. Does this sound right? more like complete re-price the whole itinerary with new pricing?

If i were to cancel and opt for refund, I would get back AUD3.8k