I wouldn't completely give up hope.
Remember in his early 20's he already picked up a massive pay day, greater than what many athletes hope for in an end of career Euro stint. Obviously that would have set him up pretty well already. He has great sponsorship opportunities and agreements in Australia due to his high profile in Australia. These add to his income and would likely disappear if he went to France.
Further, I'm sure his manager is smart enough to realise that remaining in Sydney, he would have excellent opportunities post rugby that he would be able to take a cut from also. These would likely long term be much greater value than a stint in French rugby. Also may not be there if he jumps around and is in and out of the spotlight.
I tend to think that earning slightly less, though still good money, with the view to how he will occupy his time for the next 10 or so years after he retires would be more lucrative overall, and more beneficial.
That being said, the money would be hard to compete with too and it may come down to whether he feels the money is better for him now, or what he does post career. NRL is a real concern in my view.