KingRB and the Kelpie have hit the nail on the head, that is why my son won't be doing the jetstar cadetship. It isn't worth having such a gigantic debt like that o er your head in such a low paying job at such a young age. If the starting salary was what the level 1 FO's are on, it may be worth it, but living off $58k base with such a huge loan is incredibly stupid. And, there is no garuntee of a job at the end of the cadetship. What is going to happen withh all the Qantas pilots on mou, I'm certain a lot of them will be staying at jetstar because there will be no job to return to back at qantas, there are a lot of 744 second officers who probably will jump accross to jetstar in the not so near future which is going to displace a lot of the available jobs at jetstar.
I mentioned before, it is quite achievable gaining your ppl all the way up to an atpl for under $70k. And sure general aviation might not pay you more than $58k initially, but it won't take you too long to get a hold of a turbo prop job that does.