Where to buy 18650 batteries in Australia

I have a project atm to reduce our energy bill, I mentioned it in another thread but basically, I have found lots of cheap good condition second-hand solar panels, and I am planning to run my shed off grid on an MPP Solar hybrid.

I got about 3kw of solar and most the equipment needed but batteries and a BMS, I have my heart set on 18650 batteries but dag they mark them up here in AU.

Does anyone have any insiders or suggestions to get the price:watt down, at the moment I am looking at importing at $0.35 : watt but I rather not take that risk nor the wait time.
The BMS I am probably going to build something myself based on the diyBMS as I don’t trust the look of the cheap Ebay BMS’s that don’t have any monitoring capability and there are few options at 14S with 60A charge and 100A discharge. The more expensive quality and capable alternatives are way to expensive lol.