Think alot of people are surprised it is that high and with no professional football club in the area the potential as you say is there.

Next years NRL salary cap is expected to be about 3.5mill pounds
5 years ago it was around 1.4mill pounds

The Aussie and Kiwi player train is running out of steam. I expect plenty of scouting to be going on with the PI and PNG teams at the next world cup.

If we can get the salary cap in this country scrapped and the structure of the game right, we can catch up to Australia over the next 5 to 10 years and then, ultimately, dominate again. Our population is 4 times theirs and there should be no reason for us not to be able to achieve this - so long as we stop tinkering with the structure and let all our clubs get on with making themselves successful.

That sounds great, but unfortunately our clubs have a habit of making themselves poor, instead of successful.
The income is what makes a team big, not the performance.
If crowds come in, and pay the money, and sponsorship is big enough, then the team will be big.
There is more money in the Aussie game. That is why they can spend more.

Getting rid of our salary cap will not suddenly create money for clubs to pay their big players.

My mate has just finished working for me on £40K per year and is moving to Perth Aus on £178K per year for a similar job working for the same company.

Cost of living down there is very expensive. There is no apple against apple comparison.

Off the topic a bit but interesting to look at that list- neither rugby code seems to have any real traction in about 40% of those places (if some of the periphery), and limited in two of them I'd argue.