I think being able to earn $25K in a couple of years is most optimistic.
It will take you a couple of years to get into that job and then they will not pay you 25K but mostly 20K to 24K, for the first two years.
Mustering boys are hooking into it at the second to third year of flying stage, but they are sleeping in a swag and working really hard.
First year cojoe at ESSO is more likely on $35K and the 3 - 5yr cojoe is $40K. I think the "Senior" copilot can get $50....if that possie still exists.
Giddyup.