From: Mike .
Welcome to the forum. To my knowledge this question has never been raised before so I hope you get a few replies.
I don't have a definitive answer one way or the other but I assume no such figure exists because of the many variables involved in purchasing property.
It should be so that as you add more and more properties to your portfolio the increased capital gain on the entire portfolio will provide deposits for future purchases. The amount of properties you will actually be able to purchase will be a combination of the purchase price, the debt the banks will allow you to carry, and your ability to service that debt.
Please be aware that the number of properties in a portfolio is not that important. Sometimes the right strategy may be to purchase a $200K IP and other times $50K IP's will be the correct choice. It all depends on the opportunities you can find in the market at the appropriate time. Keep evaluating your borrowing capacity every 6 months and in the interim look around for good deals. When a good deal comes along, and you know you're financial, you will be able to grab those good deals.