Mining areas do fluctuate a lot. Generally the properties rental market value is much much higher than in the rest of Australia. 

Look at the future volatility of the area and the mining company. If mining production is slowing and the tenants are great tenants and you are still receiving a great return and can secure them on a long lease could be worth looking at. 

Its not a scam but it can be very risky, check out the governments money smart website. My understanding the risks are

1/ You pay well above market rent which goes towards a deposit for the home.

2/ If you default you can loose your deposit

3/ If at the end of the rental term you can't get a loan to buy the house, again you can loose your deposit. 

4/ Money you pay towards the deposit doesn't get put into a trust account, so there is risk of not being able to recover the money

5/ what happens if the owner defaults on the loan

6/ You don't own the house while renting, and are bound by the tenancy laws.

7/ Contracts can be complex and you need a good solicitor

With your landlord insurance look into ones that are specific to landlord insurance, rather than a general insurer who insures for all other things. You need an insurer who knows   and understands IP. A couple I know of are Terri Scheer and EBM they seem to be the ones most real estates deal with.

Jamie is right logan area does have a bad stigma, an this is what will keep the prices down, there are also as I understand it traffic issues. Personally I think there will probably be better options out there for you. 

Landfills are being moved all the time. When I had to take some rubbish to the tip in Port Macquarie house were literally just outside the front gate of the tip and they were large nice and relatively new houses. Why would they build there? I recon they are banking on the tip being moved further out of town. 

So maybe look into town planning and see what the future of the tip is.

Na, not sure why would when the agent works for free unless they sell your property, why pay for them when you don't have to. 

Hi

Found this property for sale, price $265k rents for $400. Not bad, but I wonder if thats the rent for both the house and the granny flat

House and Granny flat $265,000

There is quite a bit of difference in your budget there PDimi, you could possibly look to maybe buy 2. Trust your own research, and were you thinking of any particular area of interest to you? Do you want a property close to home or in a different state? Did you want a house or unit? Did you want the high risk of the mining towns or did you want the security of inner city? You need to consider all this in your investment planning its something a buyers agent can't help you with. There are opportunites in every city every town in every state in this country. If your more specific with your question, can chuck a few areas in which you can look into.