All points are not created equal. Earning "points" twice as fast doesn't necessarily generate an award for half the spending. Typically "generic" programs assign a monetary value to the points which they use to buy a ticket, while airline mileage redemptions are based on zone and seating class without regard to the dollar cost of the ticket.

What airline(s) might you fly to Australia, and how many points would Capital One require for an economy or business class ticket to Australia?

Could you generate any miles from other sources, such as domestic flights, hotel stays, car rentals, online shopping portals etc? You can accumulate all these miles in a single airline program, but (to my knowledge) Capital One awards points only for credit card transactions.