Must have deep pockets or very little time if paying the dealership markup.

I really doubt anyone is getting a proper OEM tyre in Australia unless it's a special order. Most tyre dealers aren't aware that some vehicles have a specific build tyre fitted at the factory. eg: the CL9 Accord Euro Sport had a unique 225/45r17 Bridgestone RE040 and the high speed handling was noticeably different from the generic RE040 bridgestone. Even Bridgestone Australia wasn't aware there was a specific build tyre available (at $400 each)