Also be careful you dont get caught out on the site costs....generally they are only calculated for a standard level block with stable soil, what they call an "M" class slab. Anything outside this will incur extra costs as we found out being on a slope. So check the fine print carefully and ask lots of questions.
If you're buying land make sure you add a clause where you can back out of the sale if it's not class M or better. It doesn't mean you have to back out, but it's your choice to go through with it depending on how much it will cost for the footings for your house. Some soil types can cost an extra $10,000 + to build on.

Some land sales people will be honest with you and say which blocks contain fill once you ask them but they generally aren't upfront with that information. Same with fall.
It should be all there in the documents (in Vic it's called Section 32) for you to read in the plan of subdivision but they won't tell you