just had a quick look on google - "caravan repairs in Cairns" - heaps of companies in your area and most will do pre-purchase inspections. Price will be about $250-350 if you take the 'van to them, otherwise they will go to the sellers address and charge you about $50 or so more
Make sure you find out what they actually inspect - should include the van generally (damage, water leaks etc), axle(s), tyres, suspension, electrical, gas.
You should be there to make sure they do a decent inspection - one that's better than you could do !!
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Cheers Bruce
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