No tenant will bother contacting an agent. No house is THAT great to a renter. It is hard enough to get a PM to show you the place, much less get an email reply about how much it is.
Hey OP... about gumtree, it's pretty much instant I thought. I put an ad once and was flooded with responses.
I'm kind of curious too as I know Bulleen area and that price seems very reasonable... i though. Perhaps I am clueless...