That fee is amazing. I've never heard of anything like it before. I've noticed that travel.com.au charges their own little change fee on domestic flights, but that's about it.

IME, most TAs know almost nothing about RTWs. They ticket very few of them and they find the rules too complex for their little minds to cope with. As someone who knows what you want, I believe the best thing to do is check the online prices (eg. Qantas and travel.com.au) and then ask TAs what price they'll give you, and go to the cheapest one. I've only done Star RTWs, but I've always got $100-200 off the airline price and with no strange extra fees.