For anything but coach watch them. I purchased $8,000+ business class ticket back April 2015 now Jun 2015 for flying Oct 2015. They changed my ticket from business to coach. I know this is $6000 fare difference. Tried to bump me from first/business aisle seat to back middle seats. Maybe cause I booked my seats directly with Qantas and didn't pay their $$ fee to preselect seats through them. Plus I can't pull up the booking on their website via booking nbr I have use emails they've sent.