Use E-6 fixer from Vanbar, it is $6 for 10L worth, it's dilution is 1+9. Bleach is pricier. There are several other sites other than Vanbar for chems in Australia that I know of.
The only thing needing group buying from Vanbar would be bleach if you want C-41 bleach (which I'm using atm). There are alternatives though.