Approximate nights for a reward nightvari

[Snowman]

Folks - I know its really not that straight forward but, roughly, how many nights (at say AUD$300 per night) do I need (as a basic level HHonors member) to receive a reward night (of say 20,000 points which is I think about what I spent on a reward night in Cairns).
Back in the day, it was only like 4 and half nights for a free one, but I feel its probably more like 15 these days?
Thanks

 

[Aeolus]

Folks - I know its really not that straight forward but, roughly, how many nights (at say AUD$300 per night) do I need (as a basic level HHonors member) to receive a reward night (of say 20,000 points which is I think about what I spent on a reward night in Cairns).
Back in the day, it was only like 4 and half nights for a free one, but I feel its probably more like 15 these days?
Thanks

Quickest would be 5 stays x 1 night/stay @ $300/night to get up to 20k points with the current promotion.