"""Average 8% growth 10 years is worth $1m, you still owe $400k but have $600k in equity"""
Seriously, as a property investor you don't consider the 8% tenancy management fee, the stamps, the rates, the insurance, the maintanence into your costs. Its just a simple calculation of rent vs repayment.
Tell me how the last 10 years did for your 8% annualised growth. Don't worry, you won't the only one who got caught. Property was a good investment until 10 years ago, the smart money got out already.