When I lived in North Queensland a lifetime ago, I fronted up to the local Parks & Wildlife office each year for my Personal Use 'Roo Permit, complete with 20 plastic ear-tags for Eastern Greys and Reds, and unlimited wallabies of a half-dozen species.

The permit specified that animals were to be taken during the specified "open season".
The first time I asked what was the open season, the crusty old ranger processing my paperwork looked at me with a wry smile and said "First o' January to thirty-first o' December, mate!"

Forgot to add: the way to get more customers to buy roo meat for human consumption is to make it cheaper, not raise the price!
Sure, pay the shooters more at the box, but subsidize the middle-man as an ecology offset.