Buy, Wait or Upgrade

• Every path is measured against staying put. Each year the model works out what your housing would cost if you never bought (your current loan and running costs, or your rent) and what it costs on the path you picked. When the path is cheaper, the difference is invested. When it costs more, the difference comes out of your investments. Savings you'd make on any path are left out, because they add roughly the same to every option.
• That means your deposit only grows by investment returns while you wait. If you'll be saving extra toward the deposit, a later purchase is more affordable than shown here.
• The offset account. Before you buy, the offset balance cuts the interest on your current loan, so more of each repayment pays it down. When you buy, the offset cash goes into the new home's deposit along with your other cash, which keeps the new loan as small as possible. In the keep scenario the old loan is then fully drawn and stays on as the investment loan. That's the usual way to set it up, because interest on an investment loan is tax deductible and interest on your own home isn't. The model doesn't count the tax effect.
• The purchase happens at the start of the chosen year. The home's price grows at the property growth rate from today's price. Your borrowing capacity switches to the higher figure in the year you set.
• Stamp duty uses Victoria's land transfer duty schedule, including the principal place of residence rate up to $550k and, in the rent scenario, the first home buyer exemption to $600k and sliding concession to $750k.
• The new home's loan is principal and interest over 30 years. In the keep scenario the old loan keeps paying principal and interest at the investor rate, and the rent, less landlord costs, offsets it.
• Not modelled: income tax, negative gearing and capital gains tax, lenders mortgage insurance (flagged when the loan is over 80% of the price), land tax, bridging finance, and changes in interest rates over time.
• Net worth counts property at market value, less loans, plus cash and investments, before selling costs or tax.

Settings as of 14 November 2026. The RBA lifted the cash rate to 4.85% on 3 November, its fifth rise this year. Canstar puts the average owner-occupier variable rate near 6.74%, with competitive rates under 6.5%. APRA still assesses borrowers at 3 percentage points above the loan rate. Cotality has Melbourne home values 7.3% lower than five years ago.

Sources: Savings.com.au, Canstar, APRA, Cotality, SRO Victoria.

An illustration for thinking, not financial advice. Get a broker's figure for your borrowing capacity and a planner's view before you act.