I think it's confusing for FIFO workers because your employer will tax you per your pay period so if your paid say 12 days work in 1 fortnight and you are paid fortnightly your earnings will most likely be quite high which puts you in the higher tax bracket because once you earn so much per fortnight you then pay higher tax but the following fortnight you may have only worked and being paid for 7 days (if say you work a 3 and 1 roster) so you would be in the lower tax bracket paying alot less tax. This used to happen with dh's previous job and it took me a while to figure out and understand how it works. Regardless though it will get balanced out at the end of the financial year and you will be repaid any tax you have paid more than should have. I often don't think people understand that either though!
I definately noticed prices increased after the gst was introduced also.