Some of your arguments make no sense. So because it is a dominant sport the NRL can charge $80 bucks to $100 more to the same type of jersey in the UK.
In England Soccer is the dominant sport, it doesnt charge equivalent of $169 AUD for a jersey. They are 40 pounds...
Using the current exchange rate in comparing UK prices for Premier League jerseys vs Rugby Jerseys sold here only tells part of the story.
Some years ago the exchange rate was 3 to 1 so a 40 pound jersey was equal to $120 Australian. However today the exchange rate means that same football jersey in the UK is now worth $70. Has the jersey dropped by almost 50% to the UK buyer? No the price is the same.
A fair assumption is to take an average on exchange rates when comparing cost of living and then assuming that the average Premier League jersey is valued at around $100 or the equivalent cost to an English person in buying that jersey in their country.
Now English jerseys are not made in London or Manchester, they're made in Indonisia or Thailand or China by the gazillion load for tuppence ha'p'nny. Manchester United, Liverpool, Chelsea & Arsenal sell as many jerseys in Asia as they do in the UK.
A quick squizz at the Roosters jerseys in my closet shows the authentic 1998 away jersey was made in Australia and my replica traditional jersey was made in China. The first cost over $100 12 years ago and the second cost me $95 this year. I can't say where authentic jerseys are currently made, but even if it is in China the numbers made compared to English clubs would be much smaller.
With smaller sales volumes you have to make a larger margin on each sale for the club to make a viable profit, but you also have to take into account smaller sales mean a higher percentage per unit goes towards shop rents, staffing costs etc.
As others have said if you really cant pay $160 then buy a traditional jersey that doesnt require updating every season or buy last seasons at reduced prices.
Even if you buy a new home jersey every 3rd or 4th year, an $80 difference in cost amortised over 4 years = $20 a year or $5 per quarter or $1.25 per month or 27 cents a week.