oz is correct, however, there is a change to trend for public holidays, many people now only receive double time not double time and a half.
Your bigger name companies like Big W, Kmart, etc have their own awards and own pay rates which are slightly higher then the minimum award wage.
On average, a lot of shop assistants are employed as casuals in Australia with the average wage of $18 per hour, over 21 yrs old.
Also not everywhere offers uniform allowances or travel allowances, so one doesn't expect it.
Part time employee's can earn the same rate as full-timers or a slightly higher rate depending on the company. Part timers also get 4 weeks annual leave, but not 10 days sick leave, it is actually based on 2 weeks worth of sick leave, but some companies are now offering more s/l.
I have one job that's 2 days a week and get a total of 4 sick days, which as you can imagine is very easy to use if you happen to fall sick on those days.