I have finally managed to get the flights I wanted using my Qantas FF points. The shock came when informed of the taxes which amount to AUS$362.67. With 5 stopovers this amount seems excessive when considering that 2 of the countries I intend to fly out of have not included their departure taxes in the ticket. Adding it all up I will need to pay a little over AUS$450 for a trip of only 5 stops. I have asked Qantas for a break up of the taxes but it doesn't quite make any sense. Australian taxes come out to $88.77, a Chilean tax of $70 a US nation inspection tax of $60 and so on.
I had a booked ticket late last year to similar destinations (which was later cancelled) and the tax came out to AUS$184. A month ago, I made a booking and the taxes amounted to $174. Now I have made 2 changes to that booking and am informed that taxes have gone up.

Has anyone else encountered this?. I know there is nothing I can do but taxes totalling over AUS$450 seems a bit rich.