AS the title suggests, how much does it cost?
And how does that trade off against what you can do in terms of negative gearing?

Im contemplating relocating, and renting out our house as an investment property.

Ive heard you can claim interest as a tax deduction, Im assuming this is only if you're paying it (as in if the tennants rent covers 80% of the mortgage, the 20% that I'm paying is all I can claim for)

Are there any potential traps?
Im quite apprehensive,lately anything I touch turns to @#$%%