Ex FG et al.,
The 250/hr dual rate wasn't for 172, obviously. Last time I flew couple hours in 150/152, I paid about 80 USD/hr dual rate, but that's another country/story. Haven't flown one in the US. Or some 60 USD for J3. In the US, C172 dual would be from 140 to 200/hr, depending on area, school, model/engine. I know, can't compare with Australia nowadays etc, but strong AUD doesn't help the initial shock.
Anything else I should find out about pricing/costs of airplane flying in Jandakot or Australia in general? I saw Bunbury advertising for senior-ish instructors on AFAP, but for an hour here and there, if at all, not sure worth going over. For some complex/RG flying for CPL conversion or more substantial training, probably worth it.
Clare Prop, for comparison, US FIs normally get 30-50% of the 30-45 USD/hr rate charged by school to students, unless they are independent/self-employed. Some expensive areas and advanced training may see 70-80 USD/hr for FI, but again, school's cut is considerable, too. Something nothing out of ordinary outside Europe and possibly Australia. Just get aircraft, instructor and airport to take off/land, likely without any landing fees, either.