I am traveling to Australia soon. I am on the ETA and want to potentially extend my stay to six months. I was wondering, while in Australia of course, if I should apply for the extension of a tourist visa first and THEN have my booking adjusted (because I have round trip tickets) or if I should adjust my booking first and THEN apply for the visa.

Also, I may have posted this in the wrong forum, I wasn't sure where to post it.