g'day, you can search the website carsales in Australia to give you a bit of a feel for prices:
Used Cars - New Cars - Search New & Used Cars For Sale - carsales.com.au
I just did a quick search for you but all 964 C4's were RHD. To give you a feel for prices in RHD:
94 C4 34,000 Miles $53,900AUD = $49K USD (exchange currently ~0.91)
90 C4 50,000 MIles $51,990 = $47K
90 C4 42,000 Miles $67,500 = $61K
90 C4 109,000 Miles $59,500 = $54K
89 C4 110,000 Miles $70,000 = $64K
Prices are super exe in Australia compared to the US but left hand drive imported cars take a large price hit.
In general the price hit for LHD in Aus may be about 30% (gut feel). So even if you were to take the bottom end of the range above and discount it by 40% due to high miles and little maintenance records of your example you are still looking at $28KUSD so you would likely still be well in front after freight and duties.