Roger Mendelson has 37 years' experience as a debt collector, and runs one of Australia's largest debt collection agencies, Prushka,
He has some firm advice for people thinking of buying in an apartment complex, either for investment or as an owner-occupier.
"If the mix of investors is high, whether they're overseas or not, like over 50 per cent, then that should ring alarm bells," Mr Mendelson told ABC News Online.
"If there's a significant percentage of overseas owners, basically don't touch it, I think that the risk element is just far too high."
"The owners corporations could well run out of cash, and then you can see a scenario emerging where they can't maintain the building to the standards required," he explained.
"That could start a real slippery slide of other owners bailing out and a larger number of the units being on the market and prices then tumbling."
Given the amount of new residential high-rise units being built in Sydney at the moment and the hugely inflated property market, it'll be interesting times ahead. We'd like to buy the unit we're renting but we simply can't afford it.