Amazing amazon is good but you would be better of going with a breeder as you will pay less and they can tell you more about the animal you want to buy. Reptiles down under is a good site. Gumtree can be (though I think NSW doesn't allow the selling of reptiles on non herp classified sites such as gumtree). Facebook can be good as well. If your in Victoria like me than maybe try and get in contact with John McGrath, he is one of the biggest gecko breeders in Australia and is extremely knowledgable.