An ACIR22 is AUD2400 less than an ACIR26
Now that's a lot of margaritas in PVR

And you will also save the USD150 for the 3rd stopover in Nth America, as you will now only have one (which starts in LAS and ends at JFK) Additional note: you are required to have two stopovers outside the country of origin

From your OP, I think you chose PVR as a "relaxation spot" between LAS and NYC - because it would fit within the 26,000 mile limit and Mexico is allowed on the ticket. If you now have a surface segment, you can of course chose some other spot instead - such as the Caribbean. I suggest you peruse the AA online timetable to identify potential relaxation spots

You could still fit another flight in the 22,000 miles limit. For example this itinerary SYD-xLAX-LAS,IAH-LGA,JFK-NRT-SYD. The necessary add-on of LAS-PVR-IAH should be cheaper than LAS-PVR-NYC.