hi 'Annabelle from Melbourne' - in answer to your question yes now is a good time to buy at least second hand. go for a drive around some of the newer suburbs and your bound to find some for sale on street corners (unless that's illegal in Victoria) and many will have been used once or twice and the novelty has worn off so are still quite new. have a look on ebay too, but be prepared to travel further for a good bargain and ask to see the unit assembled. if they can do it in front of you, so much the better as you will get to see if a camper trailer is really for you as some can be hard work - we have a large canvas one and the heavy gauge ripstop can be tiring to work with after a long drive from the city to a campground, then putting up an annex that's three metres by seven metres in one piece with ten poles and three rafters and two cross beams is a job for the keen but worth the effort and you do develop a strategy to make it simpler
camping shows are mainly good for checking quality of finish of the various manufacturers and seeing what you want and weighing it up against what you can actually afford - its very easy to be impressed by the displays then you get to see the prices and disappointment can set in - but don't be discouraged as around the corner is another one that may be within or even just closer to your price range