Even then each market has different submarkets with their own characteristics and revenue/expense structures. 

Comparatively, a duplex anywhere near Sydney is around $1,000,000 and rents for around $4,000 per month — no possible way to cash flow so you’d be gambling on appreciation.

Take hedonic regression as an example, with data on prices and property features, hedonic regression allows you to treat property as just a collection of characteristics, and estimate the price of those characteristics individually. 

I am in full agreement that a positive cash flow is a very important goal, due to the fact it insulates you from gambling on appreciation, equity, and rent increases. 

I took the gamble that possible mold remediation in the basement and structural deficiences wouldn't be a greater than $75k issue. 

The Property Assessor's office is nearly always the legitimate source of information for identifying all characteristics, especially bed and bath count of a respective property. 

I can only assume its located in a rapidly appreciating market where investors are willing to suck it up for a couple of years and let price appreciation do the hard work for them (always a risky gamble in any market).

@Jane A.Stock market is more like gambling on hoping that your stock improves in my opinion.

This method  can be no better than gambling, no thanks.

If you can’t see it - it’s a gamble plain and simple.