May I suggest that QantasLink isn’t desperate to “get new starters”. What they are desperate for is already type-rated pilots to minimize costs and expenditure (and some would suggest also to lock in or “sponsor” foreign pilots hoping to gain Australian citizenship).
Here's another way of looking at it.
Qantas isn't so much 'buying' pilots, but in reality it is 'selling' Australian residency.
A bit like online piracy sites being shut down by the same government. The sites themselves were getting paid advertising from sponsors and argued they were only 'selling' a website. Movie studios argued they were in effect selling (at least facilitating) stolen goods. Selling product they hadn't created, nor paid for in essence.
Qantas will get cheaper pilots, because part of the pay deal is residency. What Qf will get away with 'paying' is more a question of what value an individual places on gaining Australian residency.