Having moved from the UK to Australia, I can say that the cost differential to the UK is quite significant. Australia is a lot cheaper a place to live. Taxes are only the beginning.
Rent is a lot less here, my much nicer house, twice the size of my UK one, costs less than half what the UK one did to rent. Transport costs less, food costs less, even furniture and some electronics costs less. In the UK, you don't just bear a higher tax burden, but everything costs that little bit more, and that makes a business cost more to run, and therefore the prices it charges must be higher.
I don't criticize the UK for this, it's high taxes and high costs do probably reflect in a higher level of public service. The price has to be paid somewhere though.