I pay about 75% of my net income to my mortgage alone and it is really tight. I have no extra money for repairs (and there are a few that are desperately needed), rates/body corp/insurance etc also are all killers.

I'm fully supportive of people owning their own home, but there are hidden costs that you don't have if you're renting (like having to call an emergency plumber because you've got a burst pipe), getting a house that needs some major structural work done to it that was missed in the building/pest inspection.

Good luck with it, but I would seriously re-look at your numbers. Ask a mortgage broker for advice as well.