Gomi Gal didnt really explain about the Aus system. It's one of the best examples of a national system in the world, maybe the best after the Scandinaviaan countries.
At tax time you fill out your tax form. If you make a certain level of income you pay the medicare levy (fee) and part of filling out the form is calculating your Medicare levy. Theres no big surprises, it's just calculated so you get less tax back if you're owed a refund. At times people have to pay more tax but usually your medicare fee calculation is simple, straightforward and not a shock.
You DON't have to pay each month like in Japan. You don't get any fucking vouchers to pay. It's all done at tax time. Mates I know who have middle income jobs don't usually have to pay extra tax to cover Medicare. It's a simple, fair system.
You only pay medical insurance fees monthly if you get private coverage. Aussies bitch and whine about private insurance and too many Aussies who can afford it choose just to be covered by Medicare. But so called expnesive private health coverage can be cheaper in Aus than the NHI is in Japan. It's definitely much, much cheaper than private health coverage in America.
As for the NHI - yep, I think a lot of it is garbage. Theres no doubt us gaijin are paying because they won't stop the old silver fuckers from abusing the system. Their fucking hospital stays are crap and yours will be too if you ever end up in hospital with the shitty conditions of J hospitals generally and the extra costs for meals etc.
BUT I always paid my NHI. I am fucking happy now I did and do.