Dunno how that works. No such thing as copilot IR under Part 61 as Amarok says.
As a Grade 2 you should be paid an additional $3,493.50 pa
As you need to hold IR, that's + $6,132
I pay my pilots a salary of $62-69k depending on the top type they're flying.
What are you flying, and where?
...I suggest that the AFAP knows exactly what you should be paid, and once you join up they will be only too happy to assist.