People are willing to pay more, so companies charge more. There is also higher cost of operating, higher wages etc. But I think all that is besides the point,

People are willing to pay more, so companies charge more. There is also higher cost of operating, higher wages etc. But I think all that is besides the point, companies want to maximize profits and if they can charge a higher price and still get a similar amount of sales to a lower price (as in Australia) they will charge high.