I haven't bought a radiator in quite a few years now, but most of the times in the past where I have I've managed to get a better deal simply going to local places in my area (specifically Essendon radiators, which are actually in airport west, just off matthews avenue, but I can't remember the name of the street) and seeing what they could come up with. In one example, they used the core from a mid 80s toyota landcruiser and adapted it and some end tanks to suit.

I haven't used one personally, but a couple of blokes I know swear by the 'aussie desert cooler' mob. Both of which aren't in Sydney, but who knows maybe they all do cheap freight anyway..