3.2 I6 == DO NOT TOUCH UNDER ANY CIRCUMSTANCES!!!!!!!!!!!!
There are good reasons that the 3.2 trades for 30% less than an equivalent D5 or V8 model...
Reliability, exceedingly expensive repairs and poor fuel economy are the main reasons
Price should be $20-21k for that year and model and set of options, or thats what I see the 3.2 trade at on a regular basis
06+ XC90 == D5 or V8 motors only
As your in VIC...
This D5
http://www.carsales.com.au/dealer/details/Volvo-XC90-2010/OAG-AD-13905393/?Cr=4
For a few K more, has far better options and is in better condition and does not have a tow bar that could have been used to haul some fat kids fat pony all over god knows where