Actually correct me if I am wrong, but in Queensland Asian house geckos are not protected, though in NSW they are on licence so it would be illegal to sell them to anybody outside of QLD unless there state doesnt have them on licence.
They are nasty little things, they compete with the native species of geckos and frogs for food, they need to cull them, good thing is they don't really seem to be in the bush up there I have only ever seen them in town areas where I have been in QLD.