Im a bit biased, we are on our second CUB camper. The first a 2001 went to Kimberley twice, and via Tanami. You couldn't kill it with a stick.
We upgraded a few years a go, got a 2014 Daintree LE, not much use, for under $18000. It is also tough and well built.
CUB's hold their value, but if you keep looking there should be plenty with in your price range that are not that old.
There are other Aussie built rear hard floor campers that Im sure would be up to the job as well.