A couple of other thoughts while I'm at it:
If buying a second hand boat, inspect the trailer carefully. Often the trailer can be a third to half the value of the boat/trailer combination and yet a lot of people don't spend much time inspecting them. You won't get anywhere for very long on a clapped out trailer and they can be expensive to bring up to scratch.
If you want to investigate brand new boats, you can buy a good boat which is Australian made in Victoria in the Castle 650. They are quite quick and reasonably priced although there is a long waiting list.
Last point is that there is a trailer sailer forum which is an excellent resource for your search.
www.trailersailerplace.com.au/ The guys on that undoubtedly deluge you with more options than you could probably imagine...