property purchases speculating not investing, page-121

"If thats not saving interest and using the banks money to my advantage then im not sure what is."

That's for sure.

You save .3% per month from your mortgage offset (assuming 7% interest rate and allowing for transaction spread over the month => 7/12/2=.3%) and pay 1.5% in transaction costs i.e. it costs you 1.2% of your credit card turnover.

On $10K turnover per month you are losing $120 per month or $1440 per annum.