Hi Mom - Ebay have cement mixers for $234 free shipping. Kennards hire for $74AUD a day. Someone near you in Port will have a mixer.
CONCRETE MIXER - 0.06 CU.MTR (2CU.FT) BARROW for Rent - Kennards Hire
Bunnings are an expensive place to buy concrete. Talk to a local construction oriented builders supply. Or call Bluey and find out their local warehouse to you. I spoke to their chemist and turned up at the Brisbane depot and they gave me a bag of HE80 (they had a large mountain of the stuff) but you probably want HE80AG if you use HE80 add aggregate yourself.
Bluey Technologies; Concrete Protection and Cement Repair Products; Construction Materials
I wanted a Sika grout and Bunnings wanted $110 to get it in, my local rural supplier got it for $80... so shop around cement should be dirt cheap... Buy the way Sika have recently bought out Bluey and Lanko but the packaging and distribution remain the same. Peter
Bluey also sell epoxy but in big quantities if your interested in EG.